I love how developers and gog treat OSTs as some frivolous addition only "supporters" buy, like a wallpaper.
"In return for your generosity you will get:
A small selection of Work-In-Progress soundtrack material, which will give you a behind-the-scenes look at the composition process, and how we arrived at the soundscape for Banners of Ruin - all assembled by our excessively brilliant composer Dan Farley."
You don't even get a complete OST? These pages should say exactly what you get, how many tracks are on the OST, and what quality is available. Why do I have to pester developers, can't gog ask these standard questions?
Steam review of the supporter pack:
"I bought the Supporter pack thinking it included in game armour variants to equip on your in game characters, like alternate skins or something, I was wrong, it is just icons and files in a folder, nothing you can use in game. I like the game but hope that this clarifies what you are getting when purchasing the supporter pack, you are only getting files in a folder, nothing that you can use or equip in game. I tried googling it prior to purchase but couldn't find any info, so I guess this ones on me lol, but hope this helps someone else. Good game but if I had known there isn't anything I could use in the game I would not of bought this pack personally."