I wanted to say that I absolutely love that when you find a third copy of a unit in the shop it get's highlighted. I want to suggest to also highlight finding a second copy. Maybe not that strong but it should light up a little bit to help specially beginners with one of the hardest mechanics in the game - rerolling.
#Feedback: Highlighted Shop illuvials in Gauntlet
thorny nymph
young abyss
I agree, maybe minor glow for duplicate and major glow for evolution