Monoprice Select Mini X Axis Stabilizer

My Monoprice Select mini V2 was making a lot of rattling noise. Especially when doing circles, I noticed that the thin metal frame on the X axis arm was resonating. I found that applying some tape tightly to the arm reduced this noise (see picture), so I tried to make a more permanent solution.

The first file is a little square piece that fits snugly in the cut out and pushes up/down on the sheet metal frame. This helped some, but I thought I would try a second version.

The second file is