I really like the idea discussed in this thread NEW filters for Hero Roster and leveling Heroes – with sample UI design mockups - BETA UPDATE POST #42 - #12 by Tato but I would also like some kind of auto-leveling.
It could, for instance, be that you you select a hero to feed all trained heroes to. It might be slightly less effective, but it will be on auto! It is one of the most tiresome thinks to do in this game; to collect new trained heroes - select your hero to level - select 10 heroes - select another 10 … - and repeat several times a day. I think you would need to ascend it yourself, but that is not really an issue.
Could of cause be extended to a more complex solution where you select all purple heroes to go to a certain hero, etc.