Yes it is heavy! I got it to 5 steps (ie 3 extra steps compared from importing it directly into BIAB).
Export from SongMaster Pro, Import to MuseScore, Copy score to new score within MuseScore, Export from MuseScore, Import into BIAB (it might be faster to type the chords in manually). The screen shots were only to show that it works loading an MusicXML into BIAB if the file is in a specific format
(But it might be useful when trying to analyze what is going wrong when importing to BIAB, it is quite easy to compare the two XML files and see what differs from the one that is working compared to the one that is not working).