o1bigtenor:
...
> Arduino is far too pricey - - - I've been considering something like
> the RP2040 - - -
...

I'd just use old stm32f100 which has two DAC which often is convenient.
If you are doing theese by yourself, remember that TQFP is easier to
solder by hsnd than QFN, also TQFP's are easier to clean.

Regards,
/Karl Hammar