Again, you just have to DO the tests, or rides. If you use TrainerRoad + powermeter where you get really good granular control of your power, in highly reproducible conditions, you'll find no relief from the suffering by pushing circles/squares/etc.

I routinely do 3 hr rides every week on TrainerRoad at preprogrammed power targets, which are hard, but I hit them, so I am quite aware of how not helpful making a conscious effort to pull up is. Ok, I get handful more watts for a few pedalstrokes, but typically it drops soon after - I attribute it since it's so inefficient to generate watts with the weaker upstroke muscles than the powerful glute/downstroke muscles, it doesn't help at all, and likely makes your avg wattage worse.


The triposition 'saving legs' is a myth as well and has been disproven in practice. You don't run significantly faster by just getting into a forward position - you run faster because you ride faster for less watts.

The 'different muscle' issue is definitely at play when doing sequential bike/run, and especially bike/swim. You can typically run pretty well even after a pretty strong bike effort. But I think it's pretty gross overstating it when you say TT bike position is using significantly different muscles than a road bike - it's not. I now exclusively train on a TT bike, but I can hammer a road bike just as hard with same wattage tomorrow on a 4 hr ride if needed, no penalty.