TerraPainter store all rules and settings for procedural splat map generation in a scriptable object : TerraPainterProfile. Saved in your project, you can export and re-use in other projects
TerraPainter supports Unity Standard Terrain so is fully compatible with all assets based on that.
Regarding TerraPainterProfile. basic operations are the creation of a new empty profile, load an existing profile and create a profile grabbing the textures from your scene landscape.
New profiles are saved in a predefined location. If required, you can change that default location.
The new setting will be shared across the entire project as we store few basic setting information.
In case you delete the file that will be automatically regenerated using default setting