I know in RPGMaker VX you can set events to play on load with a plugin though I know this is made with a different version. Looking into things a bit more there is a script command to delete saves in some versions as well. Perhaps you could use an autosave plugin and have loading a save delete the autosave? Generally those use save slot 0. It wouldn't be a perfect fix, players could still load the autosave once, but if it only autosaves at the start of a floor anyone who gets in over their head likely won't be able to escape even with a second chance.