Block Limit Fix
This mod fixes a vanilla bug that occurs when there's roughly 500k unique Blockstates. When this bug is triggered, a range of issues can occur from ghost blocks to desyncs.
Specifically, beyond 524288 states, the math for serializing the states to packets breaks down due to a misplaced cast. This bug is fixed in 1.19.4 / 1.20, whichever comes first. This mod backports it to older versions.
Thanks to Patbox for debugging this and figuring out the solution.