This photo shows two Omega thermocouples (5TC-TT-K-36-36) mounted to the top surface of my hot press plate about mid length. They are simply taped down using Kapton tape, located just outside the ski footprint. Some heat shrink tubing is applied to the thin 36 gauge wires to help protect them from cuts at the edge of the aluminum plate.
Back when I made my first press form I measured the temperature of the hotplate at several locations and found the temperature to be quite even so I decided to locate them mid length because that’s there the ski is narrowest and I could locate the TCs well in from the edge of the hotplate.