Since Lossie was the original selection for F35B I would say that a concrete runway surface is unlikely to be on the "essential" list!
All current or ex-Tornado bases (Marham, Lossie, Coningsby, Leuchars, Leeming) have about 700ft of concrete at each runway end because of the amount of fuel vented during engine run-up - would this be enough to do RVL training in without needing to resurface the whole runway?