Excellent! Thank you for offering. I will keep you on the list, should we not be able to recreate the issue on one of our internal systems.
Also curious if you have installed the newest Mac driver from 3Dconnexion. It is version 10.6.0 (October 31, 2018) and you can find it here: 3DxWare 10 Archives - 3Dconnexion US
Yes I have. It made no noticeable difference.
Just to add my own feedback to this topic encase it is helpful to someone. I had a memory leak problem with the 3dconnexion space mouse in High Sierra. It happens if I don’t have the mouse plugged in but do have the extension enabled. I had to disable the extension to be able to use Sketchup without the 3D mouse. Took me awhile to figure it out as the same thing would happen me as @slbaumgartner the OS would freeze once the leak got above 2GB.
3Dx version 4.5.0 with Sketchup 18.0.16976