In the matrix source xml file, can you try to replace :
<item id="19" name="MPE CC74"/>
by
<item id="19" name="CVIN1"/>
<item id="20" name="CVIN2"/>
<item id="21" name="CVIN3"/>
<item id="22" name="CVIN4"/>
<item id="23" name="MPE CC74"/>
Then you have to restart the editor so that it reads again the xml files.
If you want to recreate the default files, just delete them, they will be recreated next time the editor is started.
This didn't work either. In the editor these values does show up like they should, but the only selection that would stick was CV1. if i selected CV4 or MPE CC74 it would still just directly switch to CV1.
Edit: I tried a new thing..
Changing these;
<item id="13" name="Performance 1"/>
<item id="14" name="Performance 2"/>
<item id="15" name="Performance 3"/>
<item id="16" name="Performance 4"/>
to
<item id="13" name="CVIN1"/>
<item id="14" name="CVIN2"/>
<item id="15" name="CVIN3"/>
<item id="16" name="CVIN4"/>
would change the name in the vst editor but not on the unit itself, it would still use perf1 if i selected e.g CVIN1.
Thanks though for taking the time, i'm sure you'll work it out once you get home etc.