Adds a low-priority hauling job that makes your haulers merge stacks in your stockpiles. Works per stockpile, so if items are in different stockpiles they will not be merged.

Issues

As each storage building (e.g. vanilla racks, extended storage, deep storage, etc) count as a single stockpile (or technically, have their own SlotGroup - which for this mod is equivalent), stacks in different storage units will not be merged.

Notes

When I was playtesting this, Stockpile Efficiency was brought to my attention. These mods do pretty much exactly the same thing (in fact we both use the same vanilla methods for the actual hauling). The main difference is in how we keep track of what can be merged. Stockpile Efficiency searches for stacks that can potentially be merged whenever a pawn is looking for something to merge. Stack Merger keeps a permanent cache of stacks that can be merged. I haven't run any benchmarks, but I expect my mod to have a mostly constant, relatively low cpu load. Stockpile Efficiency will have no load as long as pawns don't have time to do the hauling jobs, but when they search for things to merge the cpu load will most likely be considerably larger.