Hybrid has been using a lazy DXVA based HW decoder, it must be change

[Selur]

DGDevNV is not a very advanced decoder and slow.

DGDecNV does use the current nvida decoder, at least on normal Desktop machines they are not slow in any way. (assuming your card is capable enough)

Why don't you implement NVENC decoder

There is no such thing. NVEnc is the encoder and NVDec is the decoder,... there is no NVEnc decoder,...

I can't see any selector between hw decoders in Hybrid.

That is because I just implemented it a few days ago since nobody asked for it before.
-> will be in the next release

Maybe you can add a similar simple quick selector button like StaxRip has.

the attached screenshot show how it's available in Hybrid

That said, what Hybrid doesn't support is using NVEncC as Decoder and Encoder, since that would basically kill any filtering support.
If on your machine that is the only way to get decent speeds I would recommend to stick with StaxRip or other tools which support it, since I don't plan to implement it any time soon.

Cu Selur