As the title says, the pirate appearance potion is gambling. You spend ancient coins, a premium currency, to purchase the ability to reroll your pirate on the IPG (infinite pirate generator), which can't be manipulated to get desired results, can't be undone, and can be misleading (the lighting, angle, and character poses make it hard to fully take in the details of each pirate). Gambling is not allowed in video games anymore as per EU regulations, and the pirate appearance potion or maybe even the whole IPG would benefit from a rework anyways in regards to quality of life. You should be able to save your original pirate when using the potion, with the ability to swap between pirates from the clothing or vanity chest. You should also be able to select preferences for the IPG such as gender, size, and age, favouriting a pirate should skew the generator to make more pirates similar to that one, the tavern should also be more brightly lit, and you should be able to zoom in on or rotate around the pirate you're currently hovering over.
On a more personal note, I pre-ordered the game and picked my pirate day one, I was lucky that I only had to generate a new set of pirates a few times (friends of mine were not so fortunate, and have spent hours rerolling in the IPG°). For this reason I am quite attached to her. However, if I could use a pirate appearance potion and switch between her and the new pirate whenever I wanted, or if there was a guarantee that I could generate a pirate I'd love. I truly hope that this suggestion be taken into consideration.
°if I remember correctly, in one of the early videos published on the Sea of Thieves YouTube prior to release, it was stated that the IPG was invented to make character creation easier, since players would spend less time fiddling with sliders. However, the opposite is true, and players spend hours rerolling and regenerating pirates until they get one that is good enough, not perfect, good enough.
TLDR: the pirate appearance potion is bad, you should be able to save your old pirate and/or be able to precisely choose your new one. This is a symptom of a greater problem with the IPG.
