I'm using Houdini/HoudiniEngine to create the terrain, which is regenerated when changes are made. This tool allows me to integrate Houdini's non-destructive workflow with MicroVerse, which is a great Unity editor tool for non-destructive worldbuilding. When the terrain is regenerated from Houdini, this tool synchronizes it with MicroVerse, which reapplies the non-destructive "stamps".
https://assetstore.unity.com/packages/tools/terrain/microverse-core-collection-232976
Sync regenerated terrain to re-apply height/clear stamps under structure.