not sure if you want to hear more from me lol but will give it a shot anyway.
we learn every day something when in comes to care, the more people have pacman frogs, the more problems we see and solve, the more we know.
a study on what type of exposure would affect albino and to what extend is not done and will never be, nobody would experiment on animals, therefore we operate on theories and analogy with people/other animals, with something is known and proven.
the studies were done on UVB exposure in general and it was proven that certain species of frogs require UVB for metabolism, while others are adapted live in no to low sunlight conditions and don't need UVB to their body processes. It is only logical to look for natural frog environment to learn about captive care requirements. In wild pacman frogs live buried into the dirt on a bottom on rainforest, they never or very rarely see sunlight and are exposed to UVB, they don't need UVB for their metabolism.
now with albino and UVB. most albino pacman frogs are not true albino, they have very much reduced melanin content, similar to very light skin toned people, now imagine if such a person will go out to the sun without sunscreen... imagining? ouch and fast, right? same with frogs, the less melanin you have the less resistance to UVB you posses.