Please allow heroes (and possibly others) to be used while upgrading

Hi SuperCell...

Awesome game in clash of clans :) As we reach higher levels, our king/queen takes days and days and weeks to upgrade... having them out during this time isn't fun at all and make it not really enticing to level them, as I find I'm leaving the game for those days due to boredom.

Could you please consider in the next update, allowing heroes to be used while they are levelling?

While it would also be fun to be able to use barracks, spells etc while upgrading, heroes are the main ones that are really noticeable...

Thank you for considering :)