Is H265 NVENC appropriate to fit UHD backups into BD50?

[Kilowatt]

Hello everyone!

I was trying to figure out if is worth for me to buy the necessary gear to start making physical disk backups.

First obstacle, BD100 (BDXL) disks are too expensive, so for anything under ~50GB I'm fine, but I can forget about UHD movies.

So I thought about re-encoding them to fit a BD50 trying not to loose much quality. I did a little bit of research and experimented a little bit with vidcoder.

Second obstacle, encoding time. x265 software 2 pass slow takes too much time (15+ hours), I need the rig for other purposes, not to speak of the power consumption.

H265 NVENC slow takes ~1h which is affordable, but I know is not near the quality of software encoding. So I wanted to ask you about your opinion of the results I'm going to achieve with NVENC for UHD movies in 45GB.

In your experience, Is going to produce noticeable artifacts? What would you do in my position?

Thanks!