I got it working and can currently play on a map with a few hundred inserters that need to leech fuel for themselves/targets and 2k inserters that don't need to leech with mostly 60 UPS.
But there are nasty UPS/lag spikes caused by my naive scheduling logic for half a second every few seconds. I have to fix those before I dare to release it to the public. I also have to reduce the overhead for non-leeching inserters a bit more to allow players to just use less leeching inserters instead of having to fully remove the mod when they reach endgame (still no mega base support planned though).
I keep working on it on weekends until it's done.
