The second question is if things like ffmpeg's hardware acceleration will ever be usable for video encoding? I know OBS can already utilize Nvidia GPU's Nvenc encoders in H264 and H265/HEVC variants, but I'm asking about ffmpeg's hwaccel command specifically. For example, my Windows 10 system with a GTX 1080 supports hwaccle options in ffmpeg such as dxva2, qsv, d3d11va, cuda, and cuvid. dxva2 is Windows DirectX 9, QSV is Intel QuickSync, d3d11va is DirectX 11, and Cuda + Cuvid are Nvidia. In an ffmpeg encode test, using hwaccel options of cuda or cuvid allows for faster decoding and encoding, which could translate to possibly better performance in OBS recordings when using the GPU encoder.
(Small note, I'm using a Ryzen R7 2700X and yet ffmpeg is stil lshwoing QSV as a possible hardware acceleration option, so they still have bugs like that. Thought this was kind of funny).