hm, in the longer run we definitely want to improve that selection widget. right now you can specify exactly one root and thats it. maybe the best is to go the other way round and say we just have route_basepaths and configure a separate admin_basepath which must be one of the route_basepaths and simply defaults to the first route_basepaths if not set. then the normal bundle has a sane configuration and if anything we tinker with the sonata admin configuration which affects less users. would that make sense?