@papawolf4
New and less skilled players probably get really confused by mirage and better/more experienced players just aren't bothered by him. I don't think you can really balance mirage much more cause he is meant to be that its like hiding a coin trick is really boring to adults but extremely confusing to children. The only thing that can try to do going forward is to make clones imitate healing and shielding.
I think if they add anything like the clones having 30 armour or something to imitate taking damage the ult cd would have to go up or mirage loses something for ulting. Honestly, the character is just very dependant on other players skill, not so much your own.