The issue has been closed
When the world changes only chunks that had a block update will re-render it appears
Why would you need to re-render all the visible chunks?
@extremeheat
If the world changes, all existing chunks would normally be discarded so the new world's chunks can be loaded, correct? Such as moving from the overworld to the nether.
Ah yes, for dimension changes it would make sense to unload everything like the client does. This can probably be done listening to the respawn packet and unloading like the client does.
Latest changes should fix at least part of the problem.
IssueHunt