I like the definition from the recent podcast from nostr:nprofile1qqstnem9g6aqv3tw6vqaneftcj06frns56lj9q470gdww228vysz8hqpzdmhxue69uhkzmr8duh82arcduhx7mn9qy2hwumn8ghj7etyv4hzumn0wd68ytnvv9hxgqgdwaehxw309ahx7uewd3hkcam28zl (forgetting the author he was reading). Is there a unilateral exit to the base chain? If yes then self custodial, otherwise not.