please add a way to remove a strongbox that isnt tied to a hex core
Seems that the simplest way to handle this is to delete all strongboxes within the same hex as a hex core that's being deleted. Otherwise I'd have to add something like a command, new selection tool, or a custom GUI just to handle this edge case (none of those options are preferable from a UX standpoint).
This will be introduced in 1.6.0. I'll additionally throw in a new command called "/delete-strongbox" so that older saves (or in any other applicable situation) can forcefully remove a strongbox that are left over from a deleted hex core.