Use a ballnose endmill to mill a pattern in the top face of the cable stay. If making several at once you can fill the entire face of the material with a pattern.
Use this EASEL link
Flip the material over and clamp down. As long as you are using an oversized pattern the alignment doesn’t need to be perfect.
Use double sided tape to secure material for the next cut.
Use a 1/8" square or fishtail endmill to cut the cable path and other details into the bottom of the puck.
Use this EASEL link
Cut the plate to trap the cable out of an acrylic material. Due to the small part size this is also a good time to use double sided tape.
Use this EASEL link
The design has recessed circles that are meant for rubber feet. These will help keep it in place. You can find a wide variety of 1/2" adhesive back bumpers from McMasterCarr