This little thing lets you restrict which biome a POI can spawn in by way of an "AllowedBiomes" property in the POI's XML. The value is your usual comma-delimited tags arrangement, with valid values being the internal names of the biomes (pine_forest, snow, desert, wasteland).
The .csproj is set up as though it's in a mod folder in the game's Mods folder, i.e. its references look in "../../7DaysToDie_Data/Managed".
Thanks to "I Don't Care" for a fix, and Lemonpie for prompting me to actually put this on GitHub.