Don’t know why the game doesn’t do this. Big money maker for them is players buying extra roster space. This would help the players and them AND give something to look forward to while waiting the the next exchange.
Though i know it is not something we can plan for, i always wanted this option, There are few cards that are worth an SE and a lot of us dont get them or cant get them. Hope there is a way for this to materialise
Honestly can not think of a 4* hero I want (And haven’t got) whom I’d be happy to exchange any of my 5* heroes for and I don’t keep 4* dupes unless i plan to level the dupe so I think this would be a useless feature for someone like me so I can not give it my backing. I could see it being good for F2P players and newer players though… Maybe