Example: there should be a small XP and Unit reward for achieving par or below every time you play a course, not just the first time you accomplish it (though the first time should remain a larger reward than the recurring one of course). This would give a small sense of reward for overall course consistency, rather than just the total results of each hole added together, create something to work towards, and add incentives to finish whole rounds rather than dropping out.
Similarly when playing with multiple players there should be a small reward for coming first in the group, etc. Not a big one, just enough to help it feel like an accomplishment. Could also do global or per-course achievements for “be 1st X times” or something like that of course.