Ah, ok. It sounds like you aren't seeing much (if any) change in wave size at difficulty 10 in 5.021 compared to 5.020.
Actually, doing the math I get a worst case of 82.5 ships in a wave (assuming a ship type with a 1.0 ship cap multiplier). However step 9 says for a single-type wave if it is below cap, it is raised to cap. That would bump it up to I believe 98, which is an 18% increase in wave size
. I'm guessing that probably isn't intended. Actually, I suspect step 9 only applies at difficulty 10, low AIP...aka, wave 1. Which the current patch just tried to reduce in brutality. This is because step 7 is x0.9 for Mark II, but x1.5 for Mark I. So until the first wave is Mark II, that 1.5 multiplier is enough that step 9 never kicks in.