How to efficiently level up your mastery in Idle Research.
How to Unlock

How to Efficiently Level
To accomplish this, continue prestiging to acquire more mystical flasks and also click the “change all” button on whichever flask you are attempting to level.
This will change all your flask crafting slots to be whichever you desire, increasing how much xp you gain for that flasks mastery slot drastically per second.


Thanks to JasKnightWing for his great guide, all credit to his effort. you can also read the original guide from Steam Community. enjoy the game.