Edit Abilities in Home Caves, Buy Abilities Anywhere
When ability editing eventually makes the move to home caves, make it so you can still buy abilities outside of home caves, but cannot switch them around. By doing this, you'll still achieve what's wanted by preventing people from swapping loadouts freely outside of caves, but players will not be forced to travel to home caves to buy abilities, putting them on a similar level to skins (although skins can be equipped outside of caves, because they are just cosmetic and not gameplay altering). I think it would feel pretty awful to have to make your way back to home caves to buy abilities and risk losing a bunch of marks when you have enough to buy what you want, especially when you don't have to do that with skins. The risk of losing marks while you grind still exists as well, so you're not free from risk entirely with this.