useful buildings in loot of higher level adventures?

So I just thought it would be cool if there were adventures that gave friaries or silos or watermills or village schools or even endless copper mines (yea, I know, dream on) in the reward, like they sometimes give castles and witch towers and stuff. Perhaps only adventures which are sold for gems (but could still be got from adventure search).

Just a suggestion but I think these new joint adventures weren't very popular when the idea was introduced, so getting a non-deco building in the reward could perhaps sweeten the deal?

Perhaps getting an endless copper mine from loot is a bit much. And the chances would be likely 0.04% or something similar.

Maybe a better approach would be to grant some new resource, like tokens, to be traded for the buildings in the merchant. So let's say you get as many tokens as is the difficulty level of your adventure. The Endless copper mine could cost like 50 000 tokens. This would also create a new trade currency to the game. And BB could have weekly/monthly promos for certain adventures to give 5x or 10x tokens. That would motivate people to do also the less popular adventures every once in a while.

Tokens like "Gem Fragments"?

As there's no longer a way to gift gems, this would be a good thing to keep a gem trade "in moderation" for BB and for players to get those trade options that should already be allowed.