You will never see a difference in a room, period, I would say. Your eyes are not capable of seeing such a difference at that intensity. Also look at the scale, that is a very small scale, going from 20-100 umol per colorsegment. A 90% uniformity is really not bad at all. On ICmag you can see a good topic about some measurements members did about the spread and uniformity of several reflectors. That's a recommended read if you think the HR96 is a crappy hood ;).
Also take into account that I made this calculation to illustrate why it would not work.
I would really recommend you to do a few
measurements in your room to see what the actual uniformity is. Take them at different heights at a square pattern and map them like in the reflector topic on icmag. Then see how deep your reflectors really are and what the light maintenance is, going deep into the crop. It can be a really an enlighting experience.
I don't only base my recommendations on what I calculate, but also on the results that people or companies who follow these recommendations obtain by using them. I don't guess or base my recommendations on anecdotal evidence. You will see that light calculations are in real life pretty accurate. In horticulture ppfd and uniformity is something we have to guarantee when making a proposal. The diagram about photosynthetic efficiency of light I showed you is not based on theory, but on published scientific research on cannabis sativa plants.
I would not recommend the 4 pro 1000 on this surface as it would be too much light, as I showed in the published document. If 4 other 1000W lamps would not be too much light on that surface imho says more about the efficiency of the
Gavita reflector and the philips lamp.