For informational purposes, the full initial GOG release including multiplayer seems to work in Arch and Wine (8.13) just running bg3.exe (Vulkan; have not tried DX) from bin folder. This did not require installing the redistributables or changing driver or running setup: Distributions can be manually extracted from InnoSetup installers with something like
Code
innosetup -d gameDir ./setup*.exe
. Data/Localization/language.lsx can be edited in some way to change language, or moved/renamed to default to English.