SMS will convert lines from the Trimble format to the AgLeader format. but I don't know if it will go the other way.  Torn maybe able to clear some of this up better yet. 

Trimble uses a shape file to store the lines.  All the lines for a field are stored in a single shape file.  AgLeader stores the lines in a pat file and only one line is stored per file (there are multiple files per field).  To use your InSight lines on the FMX, you will have to convert the pat files to a shape file (I suspect SMS can do that), but all lines for a field will have to be grouped into a single shape file (I doubt SMS can do that).

If you only have one line per field you stand a chance of making this work.  It will require some manual file manipulation to get them named right and it the right data structure for the Trimble.  If you have more than one line per field it will probably require some third party software to merge shape files and will be quite involved to do.  I have converted Trimble lines over for use in the InSight.  I have not gone the other way.