I have a Beige G3 with updated video and a USB card. In 4k78 and everything before it, my USB keyboard and mouse have both worked for the install and afterword. I do have to move the monitor from the updated video back to the built in video for the install, but once the OS is installed, I can switch back to the updated Rage 128 card.
I don't know if video is optimized at all, but it does work. I hope drivers come quickly....
