I'm currently on Fabric with version 1.5.4 for Minecraft 1.19.2 & I keep having multiple chests with the same item but every chest has less than a stack. I think a "Defrag" button or something that would combine all the stacks into a single chest would be a great feature, I do see how it could cause alot of lag though. You're mod is excellent!

Great idea, it might also help with performance for large systems because the system could do some indexing.