This is a super well-fitting case for the Drok DKP6012, an awesome multi-purpose high efficiency power regular I use for everything step-down.
(This is the amazon link, not affiliate or anything)
This thing can take 10-75V in and output 0-60V from 0-12A. That's 720W max. I use one to power my motorcycle via battery when my charging system dies, I use the serial UART protocol to make my own step-down MPPT, I use it to charge drone batteries from my high voltage ewheel.
This is designed to be super easily 3d-printed, it's even flipped into position and everything. No supports, not even any overhangs.
Designed in onshape, a solidworks clone in the web.
- Here's the public document. Anyone can fork and extend the design free of charge.
- here's the page to get a free account, they keep it hidden from their main site