I wasn't in love with the foot that's supplied with the ender extender kit, nor the STL they refer you to in the installation instructions. So I made up this threaded foot that can be carefully adjusted to the perfect height! The dimensions are pretty tight, so I ended up using some super lube synthetic grease to get the threads to operate smoothly.

The Y axis tensioner is removed, and the foot is slid down the T-slots of the extrusion to the desired depth.

I hope it works out for you as well!