After getting a lot of errors of the cuCtxSynchronize()-kind (the likes of T67350 etc.) , I decided to look into the code where these errors come from. Even though I could not fix them, it struck me as odd, that Blender would crash, even though the final image could still be rendered without the GPU (albeit it would take more time). So I implemented a way for the GPU to report a fatal error and thus being excluded from further rendering, instead of crashing Blender and discarding all made progress.
I would of course be willing to make adjustments based on your feedback if you are interested in this kind of error handling.
In addition to that I copied over the comments from my cuda.h-File to better describe (and complete) the CUDA-Errors.