Wow! I guess to balance it out, making a custom potion that's just the same as an already existing one might mean that it's more inefficient, or Brill might be smart and refuse to do that?
I wonder how good the Omega Potion will be? But then again, given the Research Points requirements, making anything really powerful will be similarly costly to make a recipe and then to craft... And we're restricted to the prime Elements, so that's another limit.
The smart use for potion-users would probably be making element combos that don't currently exist, like Water-Fire, Ice-Fire, Earth-Thunder and Ice-Wind? Their utility might leave something to be desired, though, so not that smart? Heheh.
Reminds me of https://tvtropes.org/VideoGame/IMissTheSunrise:
Developer's Foresight: Due to the way the weapon creation code works, there is a hard limit on the number of weapons that can be created in a single game. The limit is absurdly high, so the player probably won't even get close to it in normal gameplay, but if they do, Mahk changes his dialogue when weapon creation is attempted.
...Has RPG Maker MV gotten past that, or is the limit also silly high?
