All, I apologize for the flurry of posts lately... hopefully you don't mind be blowing up the "Hacks & Upgrades" board around here

but I am VERY excited about this new update.
I have successfully integrated the VBL fix into the G4 Mini's ROM itself, moving it inside the display driver. The driver now re-arms the interrupt at the tail of its own mode-switch routine, at the moment of the switch, before the desktop draws. No app, no Startup Items, no brief freeze. It simply boots. And because it acts at the switch rather than after boot, there is a real chance it also catches the severe hard-hang and garbled-boot cases the app could never reach. After ten clean boots on my own (five warm, five cold), I've had zero freezes.
The patched ROM is byte-for-byte identical to the standard MacOS9Lives mini ROM apart from that one driver change (verified with a full dump comparison), so every existing boot patch is left alone. It is safe to drop in only if that is the ROM you already run. If your base ROM is different, do not flash mine over it. Use the included patch, which applies the same change to your own ROM.
Install is simple and fully reversible: back up your current Mac OS ROM first, expand the download, boot from another volume or CD, replace Mac OS ROM in the target System Folder (keep the name exactly), and reboot. If anything looks wrong, restore your backup and you are back to stock. And if reflashing a ROM feels like more than you want to take on, the VBL-Fix app from my previous post still covers the mild case.
Download everything here, including the full technical write-up:
https://github.com/UnexpectedBomb/G4-Mac-Mini-VBL-FixI am especially after testers who get the severe hard-hang or garbled boot, since that is the one case my own mini will not show me. Thanks as always to Elliot Nunn for the diagnosis and the ROM toolchain, and to @n8blz and @xc68000 for the earlier testing. This is the final "native" state I had always envisioned for this solution; being a ROM-level fix, this should also drop naturally into a CD or installer, as @davecom suggested earlier. If broad community testing can prove out this ROM-level fix, we may have finally, truly put the G4 Mini's cursor-freezing bug to bed.