I understand why you couldn't directly compensate players for learned recipes after reducing the prices. The massive crown influx would be harmful and many players will already have made the difference back through tips. There are probably other reasons.

Suppose you took the difference in crown cost for all learned recipes and awarded players the equivalent value in mist tanks, according the current ~5k energy price? It would be a much more gradual stimulation of the economy than awarding crowns. Players wouldn't be able to easily liquidate and transfer them. It would require most players to actively play the game over a period of time in order to utilize them. They could only be spent quickly on low-level items.

You would need to make mist tanks stack in the arsenal, though.