Tought there was. But from memory Franko has PPC not GPU.
GPU isn't used as the rendering is entirely software driven (note there are GL ports, not sure if any are available on Amiga). The only advantage you get on RTG here is a faster bus speed and no need to do C2P.
So will a ppc version make much difference.
Yes. Further to the above, at the default resolution of 320x200 on the PPC, even the most basic C2P routines tend to hit the chip ram "write speed" wall long before any issues caused by their lack of optimisation. However, the C2P routines used were at least as optimal as most 68K versions.
ADoomPPC was actually very playable at a variety of resolutions higher than the default 320x200 on my BlizzPPC. The determining factor was more to do with whether or not the current column being rendered would fit comfortably in the cache.
Do the PPC ports have support for AGA
ADoomPPC certainly does.