Confirmed. M6 (and 6R) implement SYSEX commands 1..6, which means the following commands are exclusively for M1000:
08 Set Group Mode
09 Clear Group Mode
0A Set Bank
0B Remote Parameter Edit ******** THIS IS FOR MOD MATRIX ONLY ********
0C Unlock Bank
0D Single Patch to Edit Buffer
0E Store Edit Buffer
Basically, M6 SYSEX command 6 (Change Parameter) simply mimicks the behavior of pressing buttons on PATCH EDIT Page. Only parameters 0..99 are recognized.