Blueprints could still be retained and occasionally dropped by mobs or found in chests, providing that satisfying dopamine rush, and should not be entirely removed from the game.
Merchants could continue to sell random blueprints, though you might consider raising their prices, given that farming coins has become significantly easier in the co-op Beta.
The requirement to research food recipes at the Scribe table seems rather illogical; in my opinion, such knowledge should originate directly from Gordon, the master chef himself surely that would make more sense.
The UI issue arises from the absence of a clear distinction between researched and unresearched items; a simple yet effective solution would be to display a green checkmark icon beside those that have been unlocked.