Can confirm my android apps all max out around 550-600umol/s as well with an oppo R17 pro and an oppo A96.
I ran 40k lux from birth and moved to 55-65k depending on location around week three as I've been on 12/12 since birth this run, but usually will run around 25-30k lux for 18-20 hours if vegging. Using a uni-t bt383 and a AS803 smart Meter and rent an apogee when I buy a new light or tent. Both the lux meters are within a few % of each other.
Apogee reads 976umol/s in the hotspot and around 830umol/s for the outers, lux Meter reads 63kin the hotspot and 50-54k for the outers.
Day 56 from germ