The issue isn't "what is molo-able", it's "what can YOU molo"? Typically characters that are leveling up "late", new characters to an old game are lacking AA, gear, probably some knowledge (experience is very quick comparatively to when the game was newer or I guess I should say "less old"). Class, AA, knowledge, play style etc all factor in. Even specific zones...or mobs. I don't really know how COV plays..but I'm sure there's a cut off, and there should be..it's max level content. Prior to that..if you've put in the work..you should be able to molo selectively in most content..with the last 2-3 expansions having some areas that are a "hard no".