LosslessCut does work with HEVC, but the GUI doesn't support playing them so it generates a low-res H.264 video to use as a stand-in for previewing and then does the actual cuts on the real file.

I mostly use it for cutting up clips from an older GoPro so I don't run in to this often but I did borrow a Hero9 recently and it worked fine, it just was a bit less streamlined.