Also consider this!
When flying either 4 white or red you're out of - let's say scale.
Wo when flying 4 reds on a PAPI who tells you that you are not already on a 1.5 deg glide slope?
I'd never fly a PAPI that way. Max allowance is 3 red 1 white
Or - disregard it tell your PNF and fly a visual approach aiming point. That is what we have been thought.