What data set is this?
I am of the opinion that the Stops data | Trafiklab would be the ideal data set since it contains mapings to all the others. And seems to be made specifically for this purpose. Det svenska hållplatsregistret | Samtrafiken Some of the mapings are slightly wrong but I believe they will get better. We could even import/add both the regional and national datasets which imo seems like the ideal solution. Since it would work with every avaliable api then.
Having some sort of connection to the scheduled data seems like a good idea given it can be used by journey planners such as OpenTripPlanner 2 to correctly place the stops onto the street network