I get that you don’t want to hamper character progression by making it overly difficult to unlock devotion points from shrines, but it feels their is a missed opportunity for an extra challenge when it comes to shrines. The offerings are often already in your stash, and the enemy waves are often heroless. I feel like shrines should A) be more difficult to unlock, and B) introduce a new gameplay element, or C) Take longer than 5 seconds. Maybe introduce a randomized side quest to go kill a heroic somewhere? The point is that you have to TRY to get the devotion point.
Elite/Ultimate shrines start to spawn several heroes (i remember the one near Zaria the Carver spawn like 7 or 8 Chthonians Heroes in a row in Ultimate) and they start to ask for rarer components and in Ultimate they start to ask for relics (like Mistborn Talisman in the East Marsh shrine).
So yeah, Devotion Shrines are fine and don’t need changing.