Bike specific profiles with correction for different power meters?

I have several bikes, each with different power meters. Is it possible to allow for a correction factor to be tied to a particular bike profile, so that power data is standardised across activities? ie, I know my stages reads 5% lower than my powertaps and quarq.

Not at the moment, although it is something that we have on our roadmap. What you can do in the interim is manually adjust your signature prior to each ride to account for the different power meter. You can also do that post-hoc as well by adjusting the fitness signature up or down and save/lockā€™ing the values to the activity. HTH