It doesn't work except for the first time it's added to a save. It only has an on_init handler, which is only run for new saves or when a mod is added to a save for the first time. It should also contain a "on_load" handler, because that's what's called when an existing save is loaded that had the mod added previously.
Weirdly, the game seems to save game.player.force.deconstruction_time_to_live sometimes (often, but not always). I don't know why.
EDIT: Okay, yeah, tried it, it really doesn't work even on being newly added to a savegame. Investigation commences… (need the functionality)
