I too have this exact touch screen monitor. I bought this Vivo mount a few months earlier and affixed a LaunchPad that's first mounted on wooden board. For this purpose the stand is well made, with the perfect arm length, and no wiggle.
https://www.amazon.com/gp/product/B00YJFY3AA/ref=oh_aui_detailpage_o09_s01?ie=UTF8&psc=1
So, I purchased a second one for my Viewsonic. Unfortunately there was quite a bit of wiggle when tapping the screen towards the edges. This has more to do with the Viewsonic's light weight plastic case than the stand. I re-engineered the design based on my Launchpad install. I attached a 3/4" wooden board cut to size (painted to match the back panel) and attached it using screws where VESA mount would normally go and also used Scott brand heavy duty, double stick tape for the other areas where the board touches the back panel. The idea here was to create a sturdier back panel. Then attached the VESA mount to the board with wood screws using its 2nd, outer set of screw holes. This feat work by reducing the wiggle about 30 percent. I'm guessing the next wiggle reduction would be to a attach single pole, double VESA mount to the Viewsonic using my wooden back panel:
https://www.amazon.com/VIVO-Monitor-Mount-Adjustable-Screens/dp/B009S750LA/ref=sr_1_1?s=electronics&ie=UTF8&qid=1504404893&sr=1-1
However I'm fairly content with my current setup using the LaunchPad and real organ pistons on my keyboard assembly for most of my registration changes.
Danny B.