Yo what if we had the ability to forge, like, 20 key fragments into a chest?

Eh, maybe. I would change it to champion shards though. Think about it. You could unlock maybe 1 or 2 champion fragments but would have a moderate chance of getting anything else. It would be heavily not worth it when compared to blue essence gained by just scrapping the shards. But you would have a chance for a skin shard of some kind which would be likely meh at best or even a gem. Not a bad idea for those of us who have all champions though.