Hi Everyone!
As promised, the missing Boons for Delve heroes are live in this patch. All unlockable characters now have some form of progression that should help keep them relevant in late-game and post-game content.
The fourth playable character and every Delve hero can now be upgraded for better stats, new skills and / or new traits, allowing for powerful new party compositions in later-game Delves.
I won't get into the details of all the new Boons here, as I would have to include some spoilers for the roster of playable heroes. You'll just have to unlock the characters and see their upgrades for yourselves!
Happy hunting!