Why would you have a fixture with E40 socket which is not HID fixture ?

High power incandescents used to use E40, while this lamp is obviously designed to replace one of those...

And i think it will work no problem in E40, the E40s i seen are very well built

But the ~2..3kg would be really too much...

High power incandescents used to use E40, while this lamp is obviously designed to replace one of those...

Must be quite rare by now then. I suspect the CFL was made as "energy saving" alternative for new fixtures rather than retrofit for old ones

And besides, you could install a ballast box on the cable, or a ballast box that the fixture plugs into as is (using pulse start lamp, so that plugging the fixture in without the ballast won't cause lamp explosion)

But the ~2..3kg would be really too much...

They can hold much more than that. You can lift a 5kg+ light fixture by the socket or by the lamp screwed into it, if the lamp itself won't break

HID would work for sure better on places with longburn time. But where the burn time is shorter (~3hour or shorter per start), the HID is not suitable anymore.

And using socket as a handle on heavy fixtures is asking to break it and get some injury...
It may hold it for short time, sometimes, but it would fail long term (e.g. lamp loosening by thermal cycles,...)

Why not ? It takes few minutes to warm up, not 3 hours

The cycle life and lamp cost would be the main limiting factor. HID's life is rated for 10 burning hours per start and still effects related to starting play quite significant role in their life...

LOL! I've started watching this guy's videos recently and he's pretty hilarious. Some of the stuff is downright dangerous but he seems intelligent...even if a little irreverent, and always warns not to try this. To me, it's both entertaining and educational. Too bad he hates MV lamps. 

That's photon for you    I've seen him fire up a many KW beacon light and it lit the whole neighborhood.