Oh my God !!!
1000 thanks Pipeline, you made my day
Frankly, I began to think that it was not possible without going back and forth with the drag / drop that I did not use too much when I'm only at the stage of audition styles .
Your tutorial is excellent and very detailed and I think your method is the best and most effective.
Thank you for sharing this valuable information with me / us

There is the Pipeline solution I just applied on FL :
0 - Setup
loopMIDI 1 - In FL : Enable loopMIDI in Midi input settings
2 - In Biab : add MidiOut.dll as a VST
(Here is the Pipeline's link)
3 - In MidiOut vst : Select loopMIDI Port
4 - Done ! Hit play in Biab & FL will follow !!!