My thoughts on this topic.
Currently, when users set stores, they can only add adress, but this is not enough for use such data for any location plugin, because such data is not validated and users can add everything to these fields.
The only way is to add map locator in store settings with google map API, where users will choose exact locations which will be stored as gmap position. Also, I think that this position must be stored in two formats: as string address and as separate latitude, longitute, because many plugins use different data to sort locations.
Give me some time, I will add this to my theme and maybe show some sollutions for this