After getting a North American 32w T9/T10 preheat circline fluorescent flushmount fixture for my collection, I was surprised that it apparently came with a FS4 starter instead of the correct FS12 starter even though the fixture came with a dedicated 32w T9/T10 preheat circline fluorescent HX autotransformer ballast. For some reason, I was surprised that the ballast had an OCV of 200v rather than the 150v that I initially expected, which is high enough to trigger an FS4 starter. Is it actually true that a North American FS12 fluorescent tube starter has a lower trigger voltage compared to a North American FS4 fluorescent tube starter and did early North American 32w T9/T10 preheat circline fluorescent  ballasts from the 1940s and 1950s have an OCV as low as 150v and only fired up lamps with FS12 starters triggering and with FS4 starters not being able to fire up the 32w circline lamps on their correct ballasts back then?

As far as I know, the North American FS12 starters are electrically equivalent to the Japanese FG-5P starters, which require a trigger voltage of roughly 147v whereas the North American FS4 starters are electrically equivalent to the Japanese FG-4P starters that require a trigger voltage of roughly 200v according to my Japanese Panasonic catalogs.