TSS?
2 workouts (FTP 270):
WO1: 4x4’@300 Watts 4’ Recovery @100 Watts
WO2: 4x4’@300 Watts 2’ Recovery @100 Watts
WO2 has the higher training stress (everyone who trains, knows that), but WO1 has the higher TSS in my calculation. (I hope I miss something here!)
Anyway, TS wise, a middle distance workout (10x400 on 1 minute recoveries) is much harder, than any aerobe time trial.
Now for TSS (which I am very sceptical about) - to maximise TSS in an hour, you need to maximise NP (as the duration is given). Whether you achieve a higher NP with a constant or somehow fluctuating power output is individual (depening on your anaerobic conditioning).
Current research shows, that a “U-shaped” power output (just over threshold in the beginning, just under threshold in the middle, just over threshold in the end) yields the highes average power output.
So yes, theoretically it is possible, that at a given FTP “criss-crossing” over and under this FTP value would give you a higher NP IF your body recovers during the under parts. Highly individual.
It also comes down to FTP definition, if it is the highest power output, than by definition you can’t generate more, if it is defined for the highest constant poweroutput, than it could be possible.
Constant poweroutput is not the fastest way to timetrial for sure, U-shape is.