After getting over level 50 / 60 I no longer play the old adventures (Black Knights etc) so they just fill up in the star menu.
Could it be possible to make a buff that - when applied on an active adventure - upgraded the enemies to a higher level. e.g. in black knight, all normal troops (recruit, cavalry etc. ) would be royal troops (royal recruit, etc.) This should naturally also increase the XP you can get from the adventure. (If it would also allow for elite troops it would be double awesome)
This way I can use the adventures filling up the star menu - and get decent XP from it.