Mike
When you type in dim or o as shorthand, you get Dim7th 1-b3-b5-bb7 chords not Dim Triads 1-b3-b5.

What we're asking for is support for diminished triads.

BIAB supports all the other triads apart from diminished.

Pop, gospel and classical music often use the basic diminished triad without the 7th.

This might not be important to you if you only play jazz as jazz generally extends the chords to include the 7ths, 9th etc.