Nope, nothing as far as I can tell in any recent firmware updates. Still frustrating that I have to keep pulling my phone out whenever riding a course which crosses over itself to work out which way to go. The only (fairly useless) workaround I found was to fiddle around with the “virtual partner” but this only works if the pace you are riding is consistent AND known in advance, otherwise the grey arrow will disappear off the map in no time.
I googled this exact issue I have been having. Same thing for me - while mountain biking or trail running it is crazy the gpx/tcx/whatever course you have loaded can't somehow show you directional arrows overlaid on top of the course? I used to use workoutdoors on the apple watch and it was way easier to navigate:
https://www.reddit.com/r/AppleWatch/comments/hdowat/decided_to_run_some_beautiful_strava_art_using/
Anyways, I submitted a feature request. I have no clue how this isn't already implemented on a device that is used for...navigating. When your course crosses over another section of your course, it should be way easier to glance at your watch map to see which direction you are heading. The heading bug can help, but not when you are holding onto your handlebars and can't reach down to switch your screen.
Fingers crossed someone at garmin actually reads these!