When asking RPR to output a certain number of AOVs and using a single eGPU (or 2x eGPU) the Final Render will immediately crash.
However with the same scene and the same render settings RPR in CPU mode will successfully complete the Final Render and all AOVs will be output in the final render window.
Individually some of the AOVs (not all) will render with a GPU but it appears to be very random which ones or how many will work. But in CPU mode it does not matter, they always work.
Result (CPU only):
It doesn't matter what size or resolution of scene is used (I chose the BMW because it is more challenging). When using a GPU multiple AOVs will crash. When using a CPU they work correctly.
Other users have tested this with similar results. Hopefully they will add their own comments below this post.