Does the Mapillary Uploader supports HEVC videos?

Yes, HEVC videos should work I believe. Try uploading them using the desktop uploader beta and let us know if you have any problems: https://forum.mapillary.com/t/try-new-video-format-support-exiftool-in-the-the-desktop-uploader-beta/

In terms of the other settings, I would leave them at the defaults, but we haven’t done extensive testing to see if they make a difference (my hunch is that the difference would be minor).