If this was a thing I wouldn't have to log onto clash for a while until all of my upgrades finished.
The only way I would see this working is to make the queue impossible to cancel (like all lab upgrades), and to allow only one upgrade to be queued at any single time, with the resources paid up front. But still, if I could send the lab working for 20 days on level 6 barch, I wouldn't log on clash for at least 10 days. And that's unusual, since I'm on clash around 4-6 hours a day! :D
In conclusion, this feature would make players slightly less active, and it would be a bad idea for Supercell to implement it into the game because of that

