If I learned anything from fighting with MicroPython on far more powerful "limited environments" it would be that this is just a curious study, not a feasible choice.
I fail to see how it is dissimilar enough to avoid apprehension. Same language (Python) on limited hardware (8-bit NES, microcontrollers.) So what makes pyNES so different from MicroPython that someone with apprehension due to the latter should have no apprehension toward the former?
Wheras micropython involves running a lightweight python virtual machine, this is a compiler. It parses a subset of python and emits assembly, which then can be run on the NES.
It is sort of like a scheme to asm dsl, but rather than via macros, this appears to operate via decorators.
For future reference, though it may be unintended, the tone of your comments does seem aggressive. This probably wouldn't be a problem if they weren't so assertively wrong/misguided.
There is no python runtime running on the 6502 hardware, and no Python semantics at runtime whatsoever. Python code is only executed on the host system during compilation. Python's role here is a glorified macro assembler.