Power Meters / Powermeters (SRM, Powertap, Quarq, Ergomo, Vector, Stages, power2max, P2M, 4iii, InPower, Cinch)

If one was calculating FTP from a 10 mile tt would it be better to use average power 256 or normalised power 266?

Relative to the 8 or 20 min test value that most use, An actual hour effort is a bit harder.

So I'd add a bit.

Just me.

My FTP is currently 280 based on a 20min smashed effort with the fixed gear on the turbo. On the road bike outside id struggle to achive that without a nice hour long climb of appropriate gradient. Even then its a bloody tough effort for me.