Max Sig Identification

Candid_and_Frank

Champion avatars have an identifier when they have been leveled up as high as possible and other indicators of the ability to rank them along the way, but there is no signifier that a champ has reached max signature. This would be extremely helpful for applying signature stones. This is particularly true for champs such as 3* or 4* where plenty of people have them at max sig and have to constantly search for a champ that can use sig stones.

SummonerNR

ALTERNATIVE..
Go to your Inventory and select the type of Sig Stones to apply, then it will pop-up the list of available (non-max-sig) champs to use them on.
And then it is very quick/simple to click on each champ from within their and actually see what Sig Level they all are (to decide which you want to use them on).