After trying most of the mounts on here I decided to do my own. The extruder mount includes mounting for V3 or V4 carriage plate, and a bltouch. It is a one piece design, but the one drawback is the bottom carriage mounting screw/s require a ball end hex key to reach.

The other part of this is that I wanted to correct the 20pin cable position so I flipped the jst-xh connectors to the other side of the PCB, and made a mount to raise the PCB up. Also did a cover to hide the wires.

Thoes square nut slots in the Hemera make finding the perfect length scew a pain in the ass.

Also these designs are done in OnShape so you can find the design files in their shared files.