Zwift run pod with curved treadmill


I recently bought a curved treadmill (no engine and no bluetooth) and a Zwift run pod. I would like to know how to calibrate the pod with Zwift. The difficulty, of course, would be to have a very steady pace during the calibration process which is impossible on this kind of treadmill. Any other option?
As it is more difficult to run of this kind of treadmill, is it also possible to increase the speed displayed on Zwift by multiplying it by a factor (0.2 for example as some studies advise to do) in order to get a more realistic speed?
Thanks for your help.

Wouldn’t know a solution to be honest… The most accurate footpod is Stryd so maybe that will suit. No footpods have an effort multiplier to my knowledge. On the other hand, bicycle power meters sometimes offer left to right power correction multipliers.