Yes clear plastic shipping tape to secure the probe to the flex is what Boaphile recommends to it's buyers to secure the probe on flex, not metal tape. Reasoning behind it per Jeff is that if ever that flex had a small pin hole or crack or tear then the metal tape conducts electricity. Shipping tape works just as good with zero risks.
I haven't tried it but when my rack arrives that is how I will secure my probe from my Helix onto the flex.