When you have a lot of charts it will prompt for each one on send/import.
You have the C7 you can drag in to get the chords into Reaper timeline as markers or regions or tempo changes.
You could have an option on the C7 to write chords to Reaper as markers or regions in the color of the part markers and write the tempo changes if any in the SGU.
So rather than be prompted on each midi import/send you can just create a new midi item and write the note info in it.

From the BB midi data:
Code
Paste into a spreadsheet. List of Events in the track=	676
Status	Channel	Stamp	Bar	Beat	Tick120	NoteNum	Name	Vel	Duration	
NoteOn	13	960	1	1	0	36	C 3	117	108	
NoteOn	13	1080	1	2	0	36	C 3	70	108	
NoteOn	13	1200	1	3	0	36	C 3	117	67	
NoteOn	14	1260	1	3	60	28	E 2	92	54
======
or
======
Bass	Bass	Bass	1011:Bass, Electric, BritInvasion Ev 120				Events=676	
Index	Delta Prev	Stamp	Bar	Beat	Tick	Type	Channel_0	Name	Note	Vel	Dur	ScoreBits
0	960	960	1	1	0	Note On	13	C 3	36	117	108	2
1	120	1080	1	2	0	Note On	13	C 3	36	70	108	0
2	120	1200	1	3	0	Note On	13	C 3	36	117	67	0
3	60	1260	1	3	60	Note On	14	E 2	28	92	54	0
Code
bool MIDI_InsertNote(MediaItem_Take* take, bool selected, bool muted, double startppqpos, double endppqpos, int chan, int pitch, int vel, const bool* noSortInOptional)

Or this might be an easier way: Bypass "MIDI File Import" window


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https://stash.reaper.fm/u/ReaTrak (Scripts for Biab Reaper)
Open SGU in Reaper Instantly