How about preferring the map with highest zoom layer for a location?
About the offset:
I have attached two screenshots of the same track (recorder->select track->plot openstmap).
One with uploaded size = medium (second) and one with size = XL (first). The medium one looks plausible, the XL one has me cross the water (no I did not).
Versions: openstmap v0.15, recorder v0.19.