My biggest gripe is not knowing what cost I'll be adding to my cards during any sort of card modification events. IT DOESN'T TELL YOU WHAT COST YOU'RE ADDING before you accept it, which means lots of dilly-dallying around the same area just to add maybe that one type of berry you forgot to have to your deck (which also ruins your deck speed). THANKFULLY the dev lets you backtrack if you decide not to upgrade, but it's still left out of the blue what kind of cost you're adding.
Please add information on the card modification events that tell us what kind of cost we are adding to our card. I believe this was a pure oversight on the dev's part.