Ok, so in terms of the API I'll leave it there for now (perhaps to use with other things), but with the comments direct SQL thats fine with me.... Just wanted to save work for the plugin
@Trosty: In the app there is a Gulp task which builds the LESS into a file, could easily just have various custom less files/directories which pump into different CSS files and select them in the settings
Should be fairly simple with Bootstrap as base.