Not sure if I have the Task Manager "switches" set the same as others...
...but even when running several open PART and/or ASSEMBLY files, I see only *one* instance of Geomagic Design.exe in the Task Manager process listing. Running Dynamics at the same time is no different; i.e., only one instance of DynamicsForGeomagic Design.exe. This same information is essentially echoed in the Resource Monitor - within the Resource Monitor, memory usage seems well controlled.
Note that in the Task Manager Applications tab, the separate instances running are shown.
Closing down Geomagic and/or Dynamics results in a clean relinquishment of resources - never have seen a problem here.
Larry