Don't know if it's supported yet (4.5.2), but is there a script out there to make a specific enemy (a boss) either 1) drop a key after defeat, OR 2) unlock a lock block after defeat?
Reminder: this version, with its module is for the SUMMER CAMP, for us to experiment.. customize, ... trying things. Of course, the module is missing a lot of scripts... those scripts will be in the definitive 4.5 version.