While more and more people using zwift for their structured workouts, i often see and realize that there has to be average watt indicator for the split on the screen. Zwift shows 3s average on the screen, however users like myself needing to see the average more than the momentary numbers so can decide whether should increase the tempo or not
a simple gauge and average number of the split can be placed right under the main watt display as i illustrated with my slowly crafted paint skills 
on the other hand, number of smart trainers, tainer bikes and 2nd gen wireless groupsets are streaming great information about the gears are being used. both sram 12s and shimano 12s feeds gear information to the bike computers so as the trainer bikes such as wahoo kicker bike and tacx. as we have these data already streamed into the thin air, why dont Zwift get this info and print it on the screen. It would be a lovely addition to the hud especially while climbing up. again it has been illustrated with my mighty paint skills on the left side of the main hud