CRF is far better than bitrate, if you care more about quality than file size. There are not 2 kinds of CRF. The strategy option is about what kind of encoding mode you want, and CRF is default. You can change it to ABR if you want to choose a bitrate instead.
Constant Quantizer, another option, is pretty much an outdated mode for x264/x265 and while it produces similar results to CRF, it creates wasted bits to do so. I believe CQP is what NVENC uses as its constant quality, but the number values are different and the bitrates created are typicall yhigher for the same quality with that.
so I should just set up a level and CRF min&max?
And shall I set the VBV? I don't quite understand the function of VBV
really appreciate for your help and finally I get asolution for HDR encoding!
I wonder can I make a video about your solution?
I will indicate the source