When it arrived I found that P =
E * I was too complicated for them, it was physically sized for 0.1V
at 80A.

Heh! A lot of the old RTL and DTL mainframe computers had prodigious
low-voltage supplies, rated in the hundreds of amps, and with multiple
tens of Farads of filtering. I scrapped an SEL-840 from The Cape that had
two four-foot-long 5/8" x 2" solid copper bus-bars for the logic supply
rails in each of the six chassis cabinets.

Invariably in those old computers, you'll find at least one spot on one
bar where someone has accidentally gotten a wrench or driver across the
bar to ground. THAT must be exciting!

LLoyd