Issue Description: As players move through the world, DynMap is very slow to fill in tiles, resulting in a very spotty and incomplete map over time. The world is pregenerated to a large extent, so I cannot just do a fullrender without spoiling unexplored regions to players. Is there either a. configuration settings to improve the responsiveness of tiles or b. a way to fill in only tiles where players have explored?

• Dynmap Version: dynmap-version
• Server Version: MC 1.18.1, Forge 39.0.9
• Pastebin of Configuration.txt: https://pastebin.com/5SETL3z2
• Server Host (if applicable): Bloom.host; server's map can be seen at http://104.247.112.163:8123/

[ x ] I have looked at all other issues and this is not a duplicate
[ x ] I have been able to replicate this

Duplicate of #2075