[MC-222146] Lag crash and memory issues when loading of a valid custom dimensions containing igloo above the build limit

The following worldgen datapack causes the POI system to get crazy and the game to explode.
To reproduce

igloo at -64 260 0 will attempt to place blocks above the build limit messing up POI system with a bed location.

Attachments

After dissecting the issue and the json file, figured out what's going on:

the game tries to place igloo at the top of the world, which in this case would result in placing a bed above the build limit, which makes POI system crazy.

The data pack no longer works in 1.17.1.

If this still applies to 1.17.1, please provide an updated datapack so the issue can be reproduced.