I had emblems on Skittleskull for over a year because Skittleskull and Sabina were my best two sorcerers. I’ve since gotten better ones, stripped Skittleskull, and haven’t used her since.
But seems like you’re in a very similar situation, so definitely can be a good thing to do.
As for Ameonna, I like the logic of high titan damage. How much higher would it be compared to the next best hero? It would have to be a sizeable leap for me to make that investment.
I’ll present a third choice. Wait for Chesire Cat.
First you could get lucky during challenge festival.
But even if you don’t, it sounds hero academy will be a solid source.
If you have excess food/iron/reset tokens, then emblem now and worry about Chesire Cat later.