Spit:
You would probably post him into another empowered position just as Flt Lts were posted from one JO post to another.
With the Rear Crew Officer being phased-out, more and more JO/SO3 posts are likely to become available and will need to be filled by Masters willing to take on the responsibility. Perhaps raising the PAS cap by two levels or so for "Empowered Masters" would provide some encouragement?
The bottom line is, as with most recent changes, the concept was not fully analysed or thought-through before implimentation.
Incidently, I believe there is a Master who is running an RAF Careers Office, so these JO/SO3 posts are not necessarily limited to flying posts.