Like others I have recorded my highest power in Zwift races for a couple reasons in my mind at least. First, the draft in Zwift is much less than in real life and I am often hanging on for dear life almost like a TT with VO2 max intervals thrown in randomly. Second, I find myself often riding in a blob of racers, some of whom are at a level higher and it takes threshold efforts just to sit on their wheels. So, I find there is zero rest in a Zwift race. There is some weird modeling that Zwift does, you could have a 152 cm 60 kg rider making 180 watts TT against a 195 cm 100Kg rider making 300 watts. Both on same bike. Zwift might assign a speed of 40 km/h to one and 42 km/h to the other. But the model gets the math wrong. Short and chubby is better than tall and thin in Zwift. I never used to make more power indoors than outside but with Zwift, I do. I cannot imagine being able to race effectively in Zwift without knowing how to use your power. You must know your functional reserve capacity and know how to conserve and use it when needed in order to survive. I usually finish and have won or placed but they are always brutally hard efforts from the start to the finish seemingly nonstop unlike a race in real life where you get to sit on wheels and rest a bit. So, my power numbers are always high in Zwift.