This may be a data editor question, I am just trying to figure out if its possible to add experience to a hero unit without it being through kills. For example cashing in minerals to gain a level. I'd rather not do this through inventory though I know that's an option if it doesn't work.
Let me know if this is a data editor issue or if you have any thoughts/suggestions.
EDIT: I found the Set unit Property action can modify experience. I suppose one option is to make a research ability that would add experience through variables. That only sets the experience not adds, so I'd have to modify the variables first I think.