I think I would try to do stems and veins in the leaves just with the quilting. It would be subtle and wouldn't take away from the secondary pattern, but would emphasize that they are leaves.

embroider if you feel it's really needed. I like them the way they are.

Rename the block. :)

Missouri Star quilt co has a great video on stems. I agree it looks fine without.

I think that they do look like leaves, but I agree that they are not appearing clearly and in my opinion the green colour needs to recede more.

Doubtless you don't wish to change the colour after so much work but I don't think any other change will make much difference. I think stems might just clutter up what is a lovely design.

Exactly what I was thinking!!