it is usually the DM's job to remind players on key things that their character know but they don't. a DC 5 or 10 religion check upon seeing shadowheart's circlet or armor followed by a brief resume of shar upon success feels appropriate, the same way we can get information about intellect devourers, the descent or what a soul coin is (it's definitely not a crypto currency).
if you don't want to have a dungeon master in your dungeons and dragons video game, there are many games out there but if you do, it's a bit more difficult to find so I am glad larian choose to do it and did it well.
