I think something similar to the the supply controller in the SAMD51 (using it as an example here because I am familiar with it) as an initial project would strike a good balance between proving a lot of the IP required for more complex PMIC type things and providing useful IP that could be integrated into other projects

Hi Weston - I have been working on the specifications of such power managements systems for the last 15 years (not the SAMD51 but very close as I was working in the same company). I can help you with the specification of the various blocks (not the internals as I'm not a analog designer) as there are many things to consider to make all those analog blocks work together

If you had any insight on how to modularize everything for maximum reuse that would be great

I can come with some recommendations