As expected, the new engagement device performed extremely well at 5/16" deflection into the tire.
However there was more vibration from the rear. I'll adjust the depth to 1/4" to see if there's any improvement.
After adjusting to 1/4" depth, there was no improvement. There was also no slipping of the roller, so that's good.
Tomorrow I'll adjust down to 1/8" depth before commuting to work. If the roller slips it's so easy to pull over and readjust to 3/16" or more. All it takes is two 9/16" wrenches.