Probably not what you are expecting to hear but it addresses what users are doing to get around the present BeatBuddy Manager (BBM) and BeatBuddy (BB) limitations.
Several user-created songs have been posted with time-stretching “(In digital sound recording and editing) the action or process of altering the duration of a sound, tempo of a piece of music, etc., without altering the pitch.)”
Here’s an example of a song with time-stretching Locomotive Breath OPBkeys(flute)
Phil_Flood has posted tutorials on how to do so using Logic Pro X. Here’s a link to the search results https://forum.singularsound.com/search?expanded=true&q=tutorial%20%40Phil_Flood