1.18.2

2.1

• Description and Easiest way to replicate -
  Place one Repeating Command block placing one block continuously, And another replacing that block with a block cluster, strangely if you add the tag {NoGravity: 1b} it clears the lag up, once this lag starts it will affect the Wither Storm's block clusters and gradually get worse, it seems to be some form of a weird leak, and it could possibly be related to collision, generally it takes a while to take effect but once the WS begins picking up huge clusters it happens relatively fast

Is Flywheel's optimizations active?
Yes, all are active

I can't seem to reproduce this. Are you still able to with the latest version of the mod?

Actually, just realized my attempt to recreate this issue was with Flywheel 0.6.8 (among other changes). Gonna test on 2.1 if the issue is present. If so I may have just fixed it without knowing.

Yeah still can't reproduce. If this is still an issue let me know.