My office is not that big, so yes it is quite intense there. But, I should say just that system is capable of delivering >500 vertical melanopic lux (which is a metric based on holding the meter vertically rather than pointing "up"), and this feels remarkably bright.
Can you elaborate ? 20k lumens doesn't seem like that much ...
I see residential interior decorating guidelines at about 20 lumens per square foot for non-intense areas like living rooms[1], etc., which implies a 1000 sf office (smallish) conservatively lit with 20k lumens.
I just put 11k lumens of background lighting in a 400sf living room and I am worried it's a bit under-lit, given 12 foot ceilings.
I think that perhaps you are talking about something different than I think you are ?
[1] As opposed to kitchens where I see 50-80 lumens per square foot recommended...