Splitting hairs aside, as I said in another thread, TSS/TRIMP is far more useful than a number like W/HR. Because yes, there are factors outside of just crank power than contribute to training stress. Sometimes it's very cold. Sometimes it's very hot. My PM reads zero on the fire road so steep I have to get off and walk. But I still have to walk up that hill.

But to the OP this is inconsequential. He asked if HR or cadence made a difference in power output. I said that in general, they don't.