Good morning all,
A small point on my investigations:
A) LINK PDF -> REGISTRATION
1. put a "button" on the PDF
2. choose "MIDI"
3. choose 'Program Change'
4. enter (example) 1 0 17 5 which will have the effect of selecting the registration 4 of bank 16
B) LINK REGISTRATION -> PDF
for the continuation I use SongBook +, option "Monitor MIDI / Bluetooth", but another editor of Midi events will do the trick too.
1. GENOS: select another Registration (preferably in another Bank)
2. SONGBOOK: click on the "Delete" button to erase the old data
3. GENOS: recall the desired bank, then the registration corresponding to the PDF
4. In the Songbook Midi Monitor window, a large number of lines in hexadecimal are displayed.
5. at the bottom of this list, look for the line **** chan 01 program change 0/116/17 (0/116/17 being an example)
6. FORSCORE: click on the title line of the PDF at the top of the screen to access its properties
7. option "MIDI / OPEN" enter the four data displayed in the MIDI monitor of SongBook, namely: 1 0 116 17
It happens that several PDFs have the same code (the one displayed in Songbook +), I have not yet found a way to differentiate them.