DeletedUser103870
Now that we have multiple upgradeable buildings where you have a choice of the Top Tier (Altar Garden, Pagoda, Ship, etc), we could do with some way to change that if we decide we've got it wrong or want/need to alter our play-style. Since they all come with their own Upgrade Kits, perhaps we could use the Upgrade Kit for that building to re-choose that Top Tier (with or without resetting the Era to Current if different). To avoid making it OP, it would have to be the Kit for that building - Pagoda Upgrade Kit only changes the Pagoda and can't be used on, say, the Pirate Ship.
This would mean we had a different use for the Upgrade Kits. Several recent Events have meant that if you completed it without spending diamonds, you would have gotten enough Upgrade Kits for 1 fully upgraded building and 1 half. You can, of course, place the half-finished one, but I expect most people who rather save the building space and sit on the leftover Upgrades hoping for them to reappear in some later Event so they can get a second complete set and place a second complete Event building. This suggestion would give you something else you could do with the Kits.
This would mean we had a different use for the Upgrade Kits. Several recent Events have meant that if you completed it without spending diamonds, you would have gotten enough Upgrade Kits for 1 fully upgraded building and 1 half. You can, of course, place the half-finished one, but I expect most people who rather save the building space and sit on the leftover Upgrades hoping for them to reappear in some later Event so they can get a second complete set and place a second complete Event building. This suggestion would give you something else you could do with the Kits.