Update: sold one FCL30EX-N/28 lamp!

I have a little different setup of TVs (pictures attached). I have 3 CRT TVs, of which two are black & white, and one is color. I've also got one universal remote.
Currently all TVs get their signal with one antenna cable coming from a Sony VCR which also has two Scart inputs (one comes from PC and other one from DVD player).

Very good research and write-up!  The quantum dot LEDs first appeared in force about 20 years ago, about a decade after the OLED technology which was also supposed to make conventional LEDs obsolete.  Based on the progress so far I have a different view on their likelihood to usurp the inorganic LED.  So far it has not been possible for QD-LEDs to get anywhere even close to the system efficacy of inorganic white light LEDs, and the lifetime remains a very severe obstacle.  It is challenging to achieve even a couple of thousand hours at the high brightness levels required for practical general lighting.  Many people do not realise this, when they buy a QD LED display, that it will quickly dim in output and require replacement after a few years.  But today we have the bizarre world that people have become used to and indeed expect to replace expensive things like TV sets and monitor displays more frequently than their lights!

Perhaps the biggest advantage of QD-LEDs is the possibility to tune their spectral power distribution to achieve extremely narrow spectral bandwidths.  As correctly noted, this is of very high value to the display industry, where saturated red, green and blue components are required.  But for general lighting we require broad spectra to achieve a high colour rendering index.  In such cases, QD-LED technology would actually be a hindrance rather than a help.  When combined with their low efficacy and short life, I therefore do not envisage a time certainly in the next 20 years or so when QD-LEDs will find their way into general lighting.

What is very interesting though, is the associated technology of QD phosphors.  These do offer interesting possibilities when combined with the classic blue-pump inorganic LED to generate broad spectrum white light, and possibly with higher efficacy and better life than the existing Garnet and Nitride phosphors that dominate the LED lighting industry.  However, those themselves have already been made so efficient that we should not expect any further drastic increases in efficacy of light sources.

  Thank you for your detailed and thoughtful response! Since standard phosphors are already hitting a wall, it makes you wonder: if we use narrow-band QD-phosphors to perfectly piece together a high-CRI white light, how will our eyes handle those tiny "dead zones" between the sharp color spikes over long periods, and could this kind of hyper-engineered light secretly trigger eye strain or make objects look weird under different angles?

I don't know.

 That's okay. Do you believe that there is a certain point where too much of energy efficiency starts to be a bad thing? Can there be too much of a good thing?

Very good research and write-up!  The quantum dot LEDs first appeared in force about 20 years ago, about a decade after the OLED technology which was also supposed to make conventional LEDs obsolete.  Based on the progress so far I have a different view on their likelihood to usurp the inorganic LED.  So far it has not been possible for QD-LEDs to get anywhere even close to the system efficacy of inorganic white light LEDs, and the lifetime remains a very severe obstacle.  It is challenging to achieve even a couple of thousand hours at the high brightness levels required for practical general lighting.  Many people do not realise this, when they buy a QD LED display, that it will quickly dim in output and require replacement after a few years.  But today we have the bizarre world that people have become used to and indeed expect to replace expensive things like TV sets and monitor displays more frequently than their lights!

Perhaps the biggest advantage of QD-LEDs is the possibility to tune their spectral power distribution to achieve extremely narrow spectral bandwidths.  As correctly noted, this is of very high value to the display industry, where saturated red, green and blue components are required.  But for general lighting we require broad spectra to achieve a high colour rendering index.  In such cases, QD-LED technology would actually be a hindrance rather than a help.  When combined with their low efficacy and short life, I therefore do not envisage a time certainly in the next 20 years or so when QD-LEDs will find their way into general lighting.

What is very interesting though, is the associated technology of QD phosphors.  These do offer interesting possibilities when combined with the classic blue-pump inorganic LED to generate broad spectrum white light, and possibly with higher efficacy and better life than the existing Garnet and Nitride phosphors that dominate the LED lighting industry.  However, those themselves have already been made so efficient that we should not expect any further drastic increases in efficacy of light sources.

My little brother texted me earlier today, letting me know confirmation of an F0 tornado that occurred in my area on Saturday. Seems as if I was correct...
an F0 tornado passed through my area, reaching wind speeds supposedly of 80 mph, confirmed by the National Weather Service.
My area: Franklin Ohio/Warren County.
Obviously that could have been a very dangerous situation had that thunderstorm been stronger... had that been an F3 tornado or higher, this story/outcome
would have been very much different, and I would have been hurt or worse, of course.

Learning more about my Genesis, from what the current owner has told me, he apparently did some work to the interior lighting, changing them to color
changing LED that he can supposedly control with a remote. I'll have to look more into this, once I purchase back the car.
For the headlights, he replaced the 6,000k HID's, supposedly with the other HID bulbs I had in the glove box, which were 5000k HID's.
The reason why I decided not to use those 5,000k HID's, was because of how much dimmer they were, surprisingly... so I'll have to see if maybe those
HID lamps needed to be broken in, which would explain why they were so dim. It seems as if he likes those HID's better, so I guess maybe they got brighter
the more they saw usage.
Hopefully those interior lights aren't stuck color changing. Great for car meets I guess, but that's it. If they aren't stuck color changing, I'll have
no problem keeping those interior lights LED.

I think that post light conversion project would be cool. Indeed 175W can be kind of a lot for a post light. I think for this application a 50W HPS, 70W MH, or 100W MV, which are all roughly equivalent in brightness. They are decently brighter than your 35W HPS porch light but a good step below 175W MV. Now to choose which one...

50W HPS:
- Light will obviously match the color of your HPS porch light.
- Ballasts are easy to find.
- Bulbs commonly available in medium base so you won't have to change the socket in your post light.

70W MH:
- White light, which may or may not be desirable for you.
- Ballasts are also very easy to find.
- Bulbs pretty much only available in medium base, again no need to change the socket.

100W MV:
- White-ish light if coated, or if clear a teal that will contrast the HPS porch light which may or may not be desirable (I think it'd be cool).
- Ballasts are very difficult to find, and when you do find them they invariably aren't 120V. You can use a 70W MH ballast which will underdrive slightly, or a 100W MH ballast which will overdrive slightly.
- Commonly available in mogul base, though you can shell out some extra to get an A23 shape one with a medium base. Depending on your fixture you may or may not have the necessary space to fit a mogul socket.

You mentioned having 70W HPS lamps on hand, they are roughly as bright as a 175W MV but if you want it to be real bright that is another option. They are also available in medium base and ballasts are of course easy to find. No right or wrong answer to be honest, these are just my suggestions

MV Bulb -> MH Ballast compatibilities are not as simple as one wattage size lower. For 175W, 250W, 400W, and 1000W* lamps are completely compatible with MH ballasts of the same wattage. For wattages below 175W, it becomes more complicated, but those are rarely used for yard lights (175W and 250W are most common as far as I have seen). If you are considering using 100W MV or below then we can cross that bridge when we get there, in my opinion it's more effort than it's worth (I bought a 100W MV lamp and running it is a pain). HPS lamps are very uncomplicated in this regard as their ballasts are still widely available. 70W should be just fine if you decide to go the HPS route.

I wasn't aware that 175W and 250W are more typical, but makes sense now that you mention it as most of what I see available are 175W fixtures, including the one I have. My interest in the lower wattage MV bulb/ballast combos is partially curiosity to tinker and partially desire to keep light output low to avoid annoying neighbors as well as allow more fixtures. For example, my porch light is a 35W HPS wallpack so it illuminates the porch nicely but the front yard and driveway could be better illuminated by a post light in my front yard that currently does not work. Since it needs rewiring, I think it would be a fun project to attempt to convert that light from an incandescent fixture to a low-wattage MV or HPS fixture.

For HID lamps, almost all ballasts are magnetic, meaning resembling a transformer instead of a circuit board. Electronic ballasts start to pop up more often in wattages below 100W, and they are probably more expensive and not worth it. Reliability with these I would assume is much more variable, though I don't have anyu experience with them. Also never heard of them even existing for probe start lamps, though I could be wrong.

Sounds to me like magnetic is the way to go in cost and reliability, then - I don't see a circuit board outliving a transformer.

What is your goal with having multiple ballasts on hand? Just wondering cause if you want to be able to just run some lamps every once in a while I have a ~perfect solution for that.

Desire to have spare ballasts on hand in case a replacement is needed for a lamp I have in service, and to have some ballasts for tinkering around with converting fixtures to HID for instance

Thanks for the info! Westinghouse got Ken Rad's lamp division in 1943, but I think I heard Ken Rad branded lamps were made at the (former) Ken Rad factory in Owensboro, KY so I'm not sure how much different they are then their Westinghouse counterparts.