Reset stars per Dragon

I would like to see when you switch dragons the lvls either reset to 0 stars or have the ability to get max xp again from that level. Such as your main dragon has gotten max xp from levels 5-1 through 5-45, You then play your alternate on same levels and that dragon could get max xp from them. Max xp as in you have not played it yet and get 3 stars, 800xp, would definetly help with new dragons that just came out and future ones.

Just a thought, might have been brought up before, if so disregard.