This is really clever, glad to see some innovation still running strong. NICE!

Curious why the MCP350 was chosen over the 355? Granted the thermal result differences are small and I think you can modify it to 18V, I'd personally rather have the 355 to start with.

Also has the integrated pump top been modified over stock for better efficiency?

I just didn't see any pump performance PQ curves on the site. I'm guessing it would be similar to a stock MCP350, perhaps better due to the removed inlet 90.