I just ran a number of experiments using different MIDI styles and each and every style correctly played and notated Cdim, Cdim7, and Cm7b5. I inputted the chords as Cdim, Cdim7, and Cm7b5. So it appears as the chords are correct on the MIDI side of BiaB.

I surmise that on the RT side what you get is what the performer played. I have played a dim7 chord in place of the sheet music's dim chord many times, as long as it doesn't interfere with the melody.

Note that I have never seen a dim5 anywhere, but that may be because I input all of my chords myself. YMMV
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Sometimes, when you cry no one sees your tears
when you hurt no one sees your pain
when you're sad no one sees your sorrow
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64 bit Win 10 Pro, the latest BiaB/RB, Roland Octa-Capture audio interface, a ton of software and some hardware