ffmpeg recommends a crf of 23 to preserve 1:1 for H.264 -> h.265

I do a probably overkill CRF of 20 just to be safe. But everything looks absolutely perfect, even blown up on my 65 inch (1080p) TV

Can you share your complete parameters, so I can do the same thing for my DVD archives & other stuff?

No hard feelings if you don't want to though :)

Sure! This is the script I wrote for it. I use MP4 containers so I can import them into MAGIX (formally Sony) Vegas but it will iterate over an entire folder of MakeMKV files and convert them https://dpaste.com/DBPA9C59M

Thank you. It's greatly appreciated. :)