Some of the spells should not get this treatment, but considering they are given in the battle pass, why don’t you allow named Sorcerers to brew sorcery potions. Like the fire wall, slow fall of the such. Lightning would be excluded. (It would also allow named sorcerers to have purpose.)
The materials used to make the potions could be similar to those that you needed to get to tht level of spell. So it would be hard to make the potions. Grey Lotus for example is tricky.
It is just a suggestion to speed up the casting. I know some people nay not want this, but it was just something I was playing around with.
I truly hope sorcery gets more interaction with alchemy in the next season. Alchemy and Sorcery go hand in hand in a lot of fantasy worlds. I don’t see an issue with allowing alchemists to utilize a mix of sacrificial blood and other reagents to create sorcery potions, the cost would of course depend on the tier of the spell, I would also add a corruption mechanic to it like casting any normal spell. Being next to sorcery should corrupt you no matter what. They could also add new sorcery that can only be utilized through potions/throwing orbs, stronger poison orbs, diseases or plagues that give a dot to enemies, a cloud of blood seeking mosquitos that drain your life if you stay in it, etc.
Personally, I would prefer sorcery not be in potion form at all, that seems way too fantasy for the setting.
However, since they are already in the game, then I agree with the idea of making them craftable recipes with sorcerer thralls. Keeping them as battle pass exclusive rewards seems kind of weird. Perhaps in the next Age, when sorcery potions would no longer fit the theme, they could become craftable.