
From pgcedit, that selection is the based on the pre command:
Code: Select all
(SetSTN) Set Audio stream = gprm(12) ; Set Sub-picture stream = gprm(13)
In MakeMKV, it shows the following:

I used trial and error to determine which subtitle track corresponded to track 13.
Is there some way in MakeMKV to see the actual track numbers?