Hey !
I'm also running Carrion Crown on Foundry, and got annoyed about upscaled original maps since they're soooo pixelated! So I started making my first map using Dungeondraft and Forgotten Adventures assets.
We're starting book 3 so the map is Ascanor Lodge. It's taking me a looot of time so it's not done yet but I'd be happy to share when it is.
Also I can't access your Harrowstone map (probably because I don't have access to your Discord).
Let's keep in touch about this mapmaking process for Carrion Crown, the AP is really cool but the lack of better maps is such a shame!