I've bought Super Feet blue for my Yonex MX 100. Is there an easy way or modification to avoid that SFB cutting into the insole ? I#ve thought of putting some silicone between the rails of the SFBs.
You mean the SFB insole cutting into the shoe? Put fabric tape (hockey tape, sports tape, duct tape) layers over the underside of the SF insole. Take them out occasionally to check that the rails haven't cut through the tape.