The Techopolis Guide Book references "Flight Potions" under Skyblock Mode > Recipe Changes. Searching JEI for "flight" does not show any flight potion. Searching JEI for "potion" also does not show any flight potion.
Tested in non-skyblock mode as well.
Tested in game created from previous modpack version and in new game created in version B11.0.
Flight potion was recently removed, I think B11.0 was the first version without. It got replaced with Balanced Flight. The Guide Book in B12.0 doesn't mention it any more, so it should be fixed.
Modpack version B11.0 Mode: Skyblock mode
The Techopolis Guide Book references "Flight Potions" under Skyblock Mode > Recipe Changes. Searching JEI for "flight" does not show any flight potion. Searching JEI for "potion" also does not show any flight potion.
Tested in non-skyblock mode as well. Tested in game created from previous modpack version and in new game created in version B11.0.