A survey of large scale DT tokamak design studies shows that the confinement time required to achieve self-sustaining operation can be much less than that predicted by the recently reported neo-Alcator scaling. The excess containment is, in most cases, more than an order of magnitude larger than that required for a steady-state burning plasma. If neo-Alcator sealing remained valid to reactor conditions, means must be found to reduce confinement times to levels consistent with steady-state operation. The problem of excess confinement has not been addressed adequately in the available literature. A positive aspect is that this excess confinement is likely to be available without engineering or physics penalty. A constructive use to which this excess confinement can be put is to burn advanced fusion fuels instead of the DT reaction, and thereby reap the practical benefits of reduced energetic neutron fluxes.