The Akko Rosewood linear switch is essentially a full nylon switch. PA12 has been recognized as a refined nylon material, especially when used to make top housings. The reason is that PA12 has a low surface friction coefficient that guarantees ultra-smoothness, and it helps make the top-out sound more concentrated and solid.
Essentially, Rosewood switches and Botany switches have the same material compositions. The difference between them is the travel distance. Botany switches is the higher pitched version while Rosewood is deeper and more thocky.