ProtonDB for Steam does not collect any data of any kind.
ProtonDB for Steam will do a secure request to the protondb API to get ratings. The requests are contained per the domains the extension works on (store.steampowered.com/app/*, store.steampowered.com/wishlist/*) and never leaves those domains. These requests only contain the appid of the store page you are on, or the appid per item in your wishlist.
