Surely the best option set up is :
Wing AAR pods - yes
Boom - yes
Able to receive fuel - yes (probe & receptacle)
Centre Line Drogue - yes
That way all "allied" aircraft can be serviced
Why would the RAF pay for a boom that they don't use, just on the off chance that an "allied" aircraft might be able to use it?
If there is a need for a multi - national tanker force, then NATO can set it up can't they?