Did you see this link, posted here a month ago? Opens a whole new world where 30,000 lumens per room is a reasonable option. https://www.benkuhn.net/lux
I didn't see this, thanks for posting it! My thought process was really similar to the author's actually and I've been happy with the results so far. I've distributed the lights around my room with shades to mitigate the unpleasantness factor as opposed to going with the "megabulb".
I made a lamp that does 25k lumens (and about 20k lux at 1 meter) but when I use it to light my room from the ceiling the light is bright enough to be unpleasent. Like going out during sunny day.