I just played a game as Marin. I chose the lesser trinket Replica Cathedral for my hero power. Multiple times throughout the game I attempted to duplicate a spellcraft or triple reward spell as my first spells and the visual and audio effects for the trinket activated but the spell was not duplicated. It worked properly for tavern spells.
It’s not working at all for me, not even with Tavern spells
Just played it, it didnt seem to work for any discover mechanics.