That looks awesome, thank you for your hard work! I would love tinker with it, but I'm not sure how to abstract things connected to those supported u_controller boards? Example, 7x16 Pico unicorn hat is driven by RP2040 PIO.
PIO isn't abstracted yet, we use rp2040js which has a full PIO emulator that executes the actual PIO instruction set (MOV, SET, PUSH, PULL, etc.) cycle by cycle, including the FIFOs and clock dividers. So it's not an abstraction. it's a direct emulation of the PIO state machines, same as how avr8js runs real AVR instructions