I was recently flying one of my 250 quads like this - front props were DAL T5045 (3 blade)
one rear was RaceKraft 5051 (3 blade) and the other rear was 2 blade 6 inch bullnose.
Escs are 3 different brands/generations, DYS blheli_s, littlebee blheli_s and littlebee (regular), I am unsure of exact configuration, but they did run mix of protocols (DShot and OneShot125).
ce. If any. Thats my personal opinion.
Indeed I thought about explaining that you could, but that there were limitations and wobbles. You don't notice this much on a well tuned (PID) multicopter, more so for someone running default tuning on an underpowered one.
The stabilization code may add 10us to both left side motors, but if the motors are different, one motor may reply with more power which will cause a slight wobble while stabilization figures it out. Well tuned PIDs will handle this better.
There is a video floating around that shows someone hooking an extra battery below a motor during flight and it handles it. That is the equivalent of that motor being underpowered.