Performance issues with Dynadock after upgrading to OS X Sierra 10.12.6
The issue is mostly resolved and performance is better.  I went to displaylink.org and downloaded the latest display driver for OSX.  This appears to be the source for OSX compatible Toshiba Displaylink drivers, as Toshiba only seems to publish Windows version on their support site.  After installing the new driver a colleague  mentioned that I should make sure that mission control has screens as "Separate workspaces".   

I confirmed that I already had this setting checked, but did a test with it un-checked, and I can confirm that this made update performance worse.

So in general, having the new latest driver did seem to restore performance, however, I am still seeing per application issues.  For instance, I can drag the Safari and Chrome browsers across the Displaylink screens as smooth as butter, but dragging Firefox is choppy and typing into the browser is very difficult to do with any kind of fluidity.