That might be an interesting thing to explore with a meter on a bench just for the sake of finding out.

Does anyone have a handy AIO Beige G3 PSUs to check this? It was the AIOs that used that setting wasn't it? I seem to recall people writing that they just plugged in their ATX PSUs when they were working with the non-AIO ones.

*Edit

Mac Gurus says "Desktop chassis" so I guess that covers the AIO and desktop model while excluding the minitower based one+it's "server" version.