Well... The special input device doesn't really have to do with it. The cal script just attached to a key combo causes the issue. And if the key is fired very fast, such as holding the key down causes the issue.

It just happens that the contour has a prescribed number of times per second where holding the key would repeat at an interval dependant on the keyboard itself, more likely. My gaming keyboard passes the repeat Very fast.

I think I might have seen some other gui issues that I am testing that might be related to this but a more general issue, which I will post about after more training.

If it helps, I bound the forward and backward scripts above to ALT+right/left arrow in CbB and tested with and without the console view mostly obscuring the track view on a single 1920x1080 monitor. Holding down the key combinations smoothly scrolled now time on my PC (Win10 i7-4790K, AMD Radeon HD 5450) using a wired PC keyboard at the default keyboard repeat rate.

Hmm. OK. Thank you for the input. I have some additional testing to do then to find where my differences are.

Well, I was hopeful that changing over to Run As Administrator would have some effect on this, but it doesn't.  I don't know what is different here.  I have the same song running under the two different versions using the same CAL settings on the same Contour Shuttle settings and CbB performs completely differently than SPLAT 2017.10.  I can't make sense of it.  I know it probably seems petty, but this is a big part of my workflow!  
 
I'm really trying to be supportive of the Cakewalk/Sonar folks.  I have a LOT invested in this DAW, including a ton of time here on the forums helping others.  But as I drive about in my car to and from the office, I try to come up with reasons to keep using Sonar/CbB when Studio One works so well.  And I'm seriously torn between the two.
 
Cakewalk has always been my choice but there are so many things that Studio One is doing right and only a few tradeoffs.  The two primary being Drum Maps and 32bit VST support built in.
 
Still looking for a solution to this.

Well - for those who might find themselves reading this post (unlikely), I believe I found the issue with the "hanging".  Interestingly, it seemed to only happen on the far outer parts of the Contour shuttle - the Shuttle In Left 7 and Shuttle In Right 7.  It didn't seem to matter what I put in those positions - they freaked out CbB.  I could even put a known working command at 1 pres every 2 seconds and it just did this weird on-screen hang.  The display didn't update, yet the time was actually moving.  When released, the time was in the place it would have been if you had seen it moving all along, but you never actually saw the motion - just the end destination.
 
In the Contour Shuttle dialog, there is a setting under options to "disable speed control".  The definition of this in the documentation and forums indicates that it disables different speeds from happening, but I don't know really what that means.  Maybe for certain kinds of assignments.
 
Anyway - if I assign the "Shuttle In Left 1" to 1 time per second up to "Shuttle In Left 7" at 60 times per second with the "disable speed control" checked, it works just as you would expect by the keys assigned to each thing.  In other words, as I move the outer ring further to the left or right from center, the speed of transports FF or RW increases - and it does not hang up at the fastest speeds.
 
So - problem solved.  And now documented for all to Google.