Heads up!
One early tester of the carrier reported that the following combination might not work:
Newer 3V Mediator in combination with my carrier and a "Ragnarok" PPC board.
Apparently, the Ragnarok draws so much current that it overwhelms the DC regulator on the Mediator.
Older Mediators that supply 5V only, as well as Prometheus, Firebird, etc., are fine.
"Apocalypse" cards work in all setups.
If you are desperate to get the non-working combination to comply, you can remove the DC regulator from the 3V Mediator. My carrier will then even supply the whole PCI bus with 3.3V reversely (as well as the PPC board, of course.)
I'll amend the 1st post to incorporate this information.