For shotgun reloading outside of combat, I’d suggest not having the shotgun auto-reload when combat ends (just wait for us to press a button) but instead make the shotgun instantly fill to six of the current shell when combat starts.
That way, you don’t accidentally use an ability when trying to reload, you aren’t denied the chance to change ammo types by combat ending and although we can keep the “one shell at a time” reloading effect on the UI, we still enter combat with a full six shells.