Thomas and Kent:

This all sounded familiar somehow and I found out why.
The OLD (original / classic) ACW already has this feature in it,
at least as of the BIAB 2018 version.

From the main, full, BIAB workspace, if you click on the "Audio Chord Wizard" in the "Tools" portion of the toolbar, it opens up the "old" version of ACW.
When you bring in an audio file, set bar one etc., it already shows the tempo in bpm to 3 decimal places.

Sounds like it just needs to be implemented into the "new" ACW.
Soooo ....

Plus 1 here.
Thanks!
LLOYD