Here are some results of my testing. All testing was done within BiaB.
Steps:
1: File > New Song, Enter a range of chords
2: Save Song. This is the chord chart:
[Linked Image - Only viewable when logged in]

3: File > Save Special > Save Song as MusicXML File and save as 'MusicXML_Tests1.XML', using these settings:
[Linked Image - Only viewable when logged in]

4: File > New
5: File > Open Special > Open MusicXML File > select the 'MusicXML_Tests1.XML' saved earlier
6: Use these settings, and press OK:
[Linked Image - Only viewable when logged in]

7: Get 3 messages that 20% (or less) of the notes are triplets crazy (None of the notes are triplets as there are no notes in the song at all.)
[Linked Image - Only viewable when logged in]

8: The ending is completely different to the ending of my original song (see step 2):
Note: There are two bars added at the front, which was expected because of the 'BB Song Bar offset' value of 2.
[Linked Image - Only viewable when logged in]

So it seems that BiaB cannot either correctly write or read the XML file it produces itself.

I'm interested to see if the results work correctly with other input files.

BIAB & RB2025 Win.(Audiophile), Sonar Platinum, Cakewalk by Bandlab, Izotope Prod.Bundle, Roland RD-1000, Synthogy Ivory, Kontakt, Focusrite 18i20, KetronSD2, NS40M Monitors, Pioneer Active Monitors, AKG K271 Studio H'phones