I dont know if this would be popular, but for island i would like that a submarine base would added. In my opinion crafting, upgrading and costumizating the submarine with island materials would be nice. You can use even island glam for different submarine parts.

The submarine would be sent on voyages for rare materials, minions, glams, mounts, dyes, submarine upgrades and even treasure maps. Crafting endgame is a bit underutilized. I want to tweak my submarine to my personal liking and such. Im sure there are people who want to have the same for an airship on island. I would like also more diversity since we can choose between shark, unkio (horseshoe crab), whale, coelacanth and syldra for different types/submarine parts. It would be nice if something like rays, kraken, squids, dolphins, sea snakes, barracudas, dunkleosteos, crabs, jellyfish or other maritime animals/creatures would be added later. They could have different properties like being more efficient on shallow waters, while other being more efficient on deep waters....but that would be probably too much.

My other suggestion next to bigger pasture (its a bit torture that i cant get all rare at the same time.....more workshops would basically force me to release several of my beloved critters to optimize the pasture even more) and fields, is to add orchards for oranges, plum, apples, cocoa, bananas, peaches and such.

I hope it can be considered, when its possible to do so.

My other suggestion is since the squads are basically dead end, why dont sent them on island, house or fc house for managing/guarding. If a combine the suggestion you can manage your squads from submarine base on island too.