Hello there !
I rise once again some of the ideas I had some time ago.
1/ Uncapped free plays on regular campaigns (or at least, some way to go deeper there) : with more and more players just waiting for the next event for new crusader/skin or dungeons, it may be the right time to do it. You said you are working on tier 4 11th objectives for after the dungeon update, is there hope for that idea to be included there or not ?
2a/ Alternate missions : some runes, rubies, materials, chests,... awarded for doing a quest differently than the regular one. Or make a milestone reward system just like the challenges but more frequent or directly with the existing campaigns.
2b/ Random reward on FP : instead of just the idols, give something else for doing FP.
3/ Rune system : adding a "merge to lv X" or "merge to max lv" option.
4/ In the Play History panel, separate some data : resets, missions/ crafts and chest drop
To all that, I ...