I think you should stay with the µ-python libraries. That way, you can piggyback on their documentation instead of needing to write your own. Of course, I’ve got a half-dozen or so boards that run µ-python, including one that’s controlling my current robotics project, so I might be biased. Unless the NXP hardware is radically different from the STM32 hardware used in the PyBoard (and a slew of other ports to various dev boards), it should be more a matter of porting those classes rather than rewriting them.
I just got my Pokitto, so haven’t really looked at getting µ-python on it yet. While testing some of these things is high on my list of things to look at now that I’ve got games on it, I’m recovering from major surgery last month. I’ve got trips to the clinic for therapy every other day, and hours doing therapy of various kinds on the “off” days, and have just gotten to the point of being able to sit at a desk.
If you can provide a “.bin” that I can load (can I load µ-python off of the SD card?) that lets me get to a REPL somehow, it would expedite my testing quite a bit. I’ll figure it out eventually, but I have to deal with those other things.