This is a remix of bryanandaimee's Bike Trainer Tilt Platform. I created it from scratch in FreeCAD, but the basic idea is the same.

I already wrote about this in the comments of the original, but I wanted to test it first.
It works like a charm, so here it is.
The things I changed:

• In the center I used lacrosse balls instead of tennis balls because the tennis balls I got felt way too soft. An additional benefit is, they don't slip on my floor.
• I remixed the cup to have a curve so that there is a defined center to which the Platform returns.
• I used 4 cups with only one lacrosse ball each in the center and one on each side with one tennis ball.
• I secured the Kickr with zip-ties.

It works pretty good on my floor with the balls directly on the floor. If you have a carpet floor you may need an additional board to place it on.

The Kickr I use is not symmetrical so finding the center of gravity (the line to put the central cups on) took me a couple of tries. First I was always leaning to the left, but now it is perfectly centered.