Optim: reimplementing List.Compare to use an inplace algorithm Caused by my upcoming changes to Free<HashSet<T>> requiring IPooled(I could've worked around it, but it was better to optimize it). Although I didn't benchmark, this in theory is a straight win - 3 less loops, no need for extra pools, and also fixes a harmless-but-perf bug(remained set had more elements than expected). Tests: Build for Client target. I also need to do runtime validation with a 3player multiplayer session - I ran out of time, will done once I'm back home.