But I saw in the ML that you've relatively recently pushed lossless VP9 encoding, I'm yet to find if it is available in my Cinelerra that I built from git yesterday (and which I can't find the version of in the About page, but I got the git very little time before I built it. I built it from master branch. The tag in git is 2022-05.)
Under "webm", there is vp9 -alpha-lossless that Andrew created and it should be in your 2022-05 git as it was checked into git on 08-Mar-2022.
To me it appears to be much better quality than h264/mp4 at the expense of file space used - about 12 times larger.