Official comment
Rob,
It's not so much about the DMX channel number, more about the fixture number. Your PARs should be set as PAR1, PAR2, PAR3, PAR4. If you wanted them to work in pairs, it would be PAR1, PAR2, PAR1, PAR2 (for example).
To figure out how different numbering would make a difference in the output, open the lighting panel and check out the macros - they'll show the different colours, fades, and movements for the different fixture numbers.
