TinyGL is no longer running on top of Rave3D indeed, therefore a Rave3D driver for the R300-R500 series was never developed. And of course the Warp3D wrapper (Goa) still runs on top of Rave3D drivers, and only those. It's also the reason why in recent MorphOS you can't run TinyGL applications on R100 Radeons and Voodoo cards, for those, no direct TGL driver exist, only a Rave3D one. The only cards where both drivers exist - for now - are R200 Radeons.

However, it would be possible to make a Rave3D "backend" driver, which uses TinyGL or its drivers to render, which would allow Warp3D and its applications to run on R300 and above (as new drivers for even newer Radeons might get developed. The only reason this don't exist, is that it really wasn't a priority for key people working on 3D stuff, and with that, lack of time, and expertise from others. Not to mention the aforementioned key people might be busy with other MorphOS components as well.