Can I run different versions of DeskPack on the same station?
The answer is 'no' and 'yes'.
No: When upgrading your station, all compatible Adobe® Illustrator® versions will be upgraded to the same DeskPack version you are installing.
So you can't choose which Adobe® Illustrator® version you want to update.
Yes: When you have an Adobe® Illustrator® version running which is not compatible with the DeskPack version you are installing, the unsupported Illustrator® version will not be upgraded.
For example, you have a station with Adobe® Illustrator® CS5 and CS6, both running DeskPack 12.1. When upgrading to DeskPack 14, the Illustrator® CS6 will be running DeskPack 14 afterwards, but CS5 will still be on DeskPack 12.1 as DeskPack 14 does not support CS5.