Have a BAH booking to IAD in Aug in PE and whilst currently no Avios availability in J on the earlier of the 2 return flights, was trying to work out what the UuA would be if I was able to swap to the later flight and then upgrade
Currently PE Avios would be..

Whilst the CW rate is

Is the UuA Avios the difference between the 2 rates?
And if so is it the new RFS rate?