There was some discussion on the discord about adding some bonuses to the actual Craft Wand and Brew Potion feats to reflect actual expertise in those things.
What if the Pack capacity for each thing was passively increased with the respective feat?
Wands could get a bonus +2 wands bringing your total to 10.
Potions could get a bonus +10 potions bringing your total to 160.
This would also facilitate selling either item without being slammed with the snail speed.
An alternative might be to turn off the slowdown while inside the well, the creep or a quest area.