To qualify, I don't think that most players are going to invest points in a skill that will maybe be used once and then ignored. I also feel like wandering around in Dungeon Fantasy with a loaded heavy crossbow is asking for an accident. I also don't think that the average encounter distance in DF is likely to make investing in a crossbow feel like a good buy (even without higher tech weapons). In any case, I'm not talking about the realism of the crossbow, I'm talking about the 1-second round which feels totally unnecessary and makes crossbow use feel like an unfun slog.
Battlesuit by Steve Jackson used dots instead of hexes. That's the only one I can think of.