I have looked for this topic and hope it hasn't been raised before. I have imported from MID to nwc but am rather baulking at the effort of deleting the key and time sigs from each bar. Can I use a user script to do this or is there another way to manage the MID file import?
Oops I have solved this myself. Save as MIDI then re import to nwc and all is well.
If you have a good text editor you can export to NWCTXT and (more) easily take out the objects you don't like. After you save it and read it back into NWC2 it should be ready to go, or close to it anyway. A recent user tip (https://forum.noteworthycomposer.com/?topic=6465.0) by Rick G. might also be helpful in this area.