I wouldn't expect them to add those things to the island itself, but a retainer bell in Moraby would be nice. (And one in Quarrymill for PotD too.) There are bells in Mor Dhona so they're not functionally restricted to being in large cities.

Eureka and Bozja indicate that aetherytes inside instances are possible, but I don't know if it would be more straining with multiple instances versus one big multiplayer one.