I ran YDL on mine back in the day and had everything working... but it's been a long time. I'm pretty sure it was newer YDL than 3.0... probably 4 or 5? Are the YDL update repositories even available anymore?
Interestingly I found this note from YDL2.3 Installation, it generates a different error message but it's not working.
I took the settings-image before restart. Now I only get a blank-screen. I have to set xserver back to the former fbev-driver (vesa-driver)
There are lot's of old PPC Macs that are equipped with these r128 cards, so finding a working solution for Linux/PPC with 3D support will be a big deal.