I have the 2016 Qidi Tech 1, they've beefed up the Z axis rods to 10mm from 8mm, so the shim isn't as needed. However, I am in the process of plugging the holes in the bottom of the machine so that random bits of junk don't fall into the circuitry underneath.

I took inspiration from here: https://www.thingiverse.com/thing:1412738.

Do note, I haven't printed this yet and confirmed my measurements. I will update once I have.