...I'm replying to this again because it just occurred to me that BiaB's substitution of my A2 chord with an Asus2 chord is inconsistent with what you said in your post. IOW, if BiaB considers a sus2 chord to be a 2 chord, why is it changing my 2 chord to a sus2 chord when it imports my XML file?
Whether BIAB shows the chord as A2 or Asus2 depends on the selection of choices in Display Options. I've highlighted these on the graphic below.
At the end of the day, though, whatever is displayed (i.e. Asus2 Aadd2), the chord is an A2 -- as shown in the list of substitutions that Matt posted.
Regards,
Noel