Usable force should be about 5 Nm in this moment. Electronics start having a mental breakdown above that level.
This is the reason why wheel started feeling bad at higher forces. Current control is actually very good until 5 Nm. After that there are huge deviations, we are talking about 20 - 40 % difference in expected output vs reality.
Notchiness is still there. I won't even try removing it until full 12.5 Nm are extracted from the wheelbase. Strength is the priority
Edit : The noise in the previous demonstration videos is because of the bad current control. Motor starts squeaking above 5 Nm. If filmed at 5 Nm that there would be no squeaking noise.