Don't think that to far, the prototype will sitting in hangar pdti until buried in dust lmaoo, the best is we selling that to china same amount we paying to KAI...are we gonna get KF-21 with flying boom for aerial refueling?
AFAIK KF-21 don't have version with probe - drogue, for prototype or production model.
We don't have tanker with flying boom tho, and I think back then when we joining the program, one of the requirements is using probe - drogue for for our IFX.
Maybe the prototype that we will receive will be used to develop P-D refueling system?