Hello!
The town of Fort Kent appears twice in the list of cities/towns in Maine on CityStrides:
I am pretty comfortable and familiar with OSM. It appears that the smaller town is the US Census boundary and a “locality”, and the larger town is the town boundary on OSM - see OSM search here. fort kent, maine | OpenStreetMap
All this being said, I think the larger town boundary is likely most appropriate for CS.
Thanks for any help!