I had an issue where the repeated flexing of the bowden tube in the tube fitting caused the fitting to fail (destruction of the stainless steel teeth). I decided to try and reduce the flexing load on the bowden coupler and originally did this by isolating the wires with dpetsel's design. Later I decided to try to add some support for the bowden tube itself and designed this remix.
Amazon Basics PLA
I have printed with and without supports. I've tapered the ziptie grooves so that the overhang is ok without supports.