It's not a gimmick when the serious overclocking people do custom VBIOSes. Similarly for miners. That's when you need the recovery switch if things go wrong.

TIL about custom VBIOSes.

Why don’t the OEMs of GPUs aimed at OCing just ship with a BIOS that exposes more tweaks through software though…

Custom Video Card firmware has been around a long time. It was possible to convert PC video cards to Mac use by flashing them. When I was faffing around with PPC64 Macs (I mean hey I got it for free) I picked up an ATI card on ebay that had been flashed.

I had sleep issues. It was the lowest-end G5. I ended up recycling it.