As a general with with libbitcoin, if you change any forks you need to resync the store. If you add a rule that is not yet active, then you can get away with the rebuild/reboot over the same store, and we don't prohibit that. there are far too many rules and interactions to try and figure out what to revalidate. Core just hardwires all forks, so from that perspective there is only the next one to consider.