Hi Franky
I just created a username to reply to your request...
I have an original VR-09 which I have upgraded to version 1.12.
I am using your CTLR VR-09 Editor to edit synthesizer sounds.
I have edited the original "JP8 Brass" as you suggested, and merely changed the Pitch Envelope (which has an obvious effect on the sound).
I saved the sound to a Registration, and switched off the VR-09.
I then restarted the VR-09 and I can confirm that it definitely DOES update/overwrite the ORIGINAL MASTER sound for "JP8 Brass"!!!!
I tried to restore the original "JP8 Brass" sound, by saving/updating/overwriting a different unmodified, factory sound to the same registration number, but the modified "JP8 Brass" remained under the "Synth" area!
I also tried switching off and switching on the VR-09 a number of times, but the sound remains changed!
Fortunately, I only changed 1 setting, so I repeated all the steps above (edit/Re-set Envelope to original Settings, save to Registration, Switch Off), and it updated/overwrote the modified "JP8 Brass" under "Synth" area to it's original settings.
I am extremely surprised and totally disappointed with these findings, because I was convinced that it is impossible to update/overwrite any original master sound (which I thought were "read-only".)
But was I wrong!!!!
:-o