To avoid any additionnal weight on the front of the carriage, I decided to go with a support mounted behind it. This support allows for the whole range of movement and also allows to tie cables on it thanks to the three holes on the top. The touch sensor is only 1.5mm upper than the extruder.

The openscad file is also present if you need to do some adjustments.

The latest files are available of my github repository: https://github.com/clementleger/3d_parts