If you are having problems with slowdown of your 3Ds Max viewport when changing any parameters within Walls & Tiles or Mosaic, this is how you can solve it. Autodesk changed their viewport preview calculation algorithms from Max 2012 to 2013 and 2014, and again 2017. While Walls & Tiles is a scripted material which includes a complex shader network, the preview calculation when using the viewport preview can be very slow. 

You can change this by going to the viewport settings and  "Display Performance". There adjust the parameter Baked Procedural Maps to something like 256 or 128 instead of 1024. This should improve response speed significantly. The disadvantage is that the viewport preview resolution will be lower, but it´s at least fast enough to work with.