hi - encoding really slow

[Selur]

i dont remember hwaccel initialization return error. where would i see this?

You would see them when calling the different ffmpeg calls I asked you to try.
In case they don't throw this error vpu decoding should be used.

any instructions how to setup and use Avisynth and Vapoursynth with hybrid?

Vapoursynth will be used, when "Filtering->Support" is set to "Vapoursynth" and a Vapoursynth filter is used. Sadly there is no free VPU decoder for Vapoursynth. Hybrid does support using DGDecNV (associated files and the license.txt would need to be copied into the vsfilters/DGDecNV folder), but that isn't free.
Usage of Avisynth can be enforced using "Config->Internals->Avisynth->Always use Avisynth", when "Filtering->Support" is set to "Avisynth" and one could use FRIM as a free vpu decoder supported source filter by enabling "Filtering->Avisysnth->Misc->Support FRIM".
-> ARGH, just checked, FRIM doesn't support HEVC hardware decoding.

=> So the only way to get hardware hevc decoding is either through FFmpeg or DGDecNV.
Your best change is probably ffmpeg with "-hwaccel cuvid" (see: https://trac.ffmpeg.org/wiki/HWAccelIntro, which isn't supported atm. in Hybrid, but I could add support for it fairly easy), but that only makes sense if that works and helps. (posted an appropriate call above, btw. if you test those calls you can also check whether is helps if you remove the '-threads 1' part, which limits the software decoding threads)

Cu Selur