I don't use toolhead boards. This is how I relieve wire strain on the Calamity toolhead designed by lukeslabonline.com.

I printed in PP-GF30. 0.5mm Nozzle, 0.25mm layers. 5 walls, 6 top/bottom 40% gyroid. PP needs the extra walls.

The back mounting screws are a tight squeeze requiring careful use of ball end hex keys. I doubt this will be the last version, but until it breaks it's rocking out as is.

Should accommodate ~½" to 5/8" umbilicals.
 

BOM:

• 4x M3x6mm BHCS - base plate mounting, no room for washers :(
• 2x M3x10mm BHCS - top of halo attachment, can be longer
• 2x M3 washer - metal on plastic, use washers if when you can
• 2x M3x4x5 heat sets
• 2x 4"x0.1" or smaller zip ties. I use these for temperature resistance