Instead of YouTube's HDR->SDR conversion you are free to use your own conversion LUT with mkvmerge. As I posted above, here are some links for info:

- Workflow and a valuable LUT: https://www.wesleyknapp.com/blog/hdr

- Some DaVinci Resolve Settings to use on SDR monitors: https://youtu.be/4izJfgRtkZE (though I upload 4K60 HDR at 37.5Mbit) which is enough for me slow content.