Buddy tanker missions are a thing and it is what the US Navy is preparing the new MQ-25 for. Beforehand, almost 1/3 of a carrier’s F-18s were set aside for these missions, stealing away from possible combat sorties.You also need to take into account the tanker has to fuel Kaan and make it back itself. And tankers usually refuel multiple times, but lets say even 1 tank full is useful. Regardless, the tanker needs to be many times heavier.
IMO the duty of an ANKA 3 tanker will be to compensate for external fuel tanks on stealth fighters, not for refueling them up to the brim.
Problem with the idea of using existing or modified drone tankers to refuel Kaan is different as I alluded to. We only have one stealth fighter, Kaan. Kaan doesn’t have a probe but a receptacle, same as our F-16s. Kaan is huge and have two F110s, and will have two TF35Ks that will devour its fuel load. Kaan won’t have a probe for refueling, it just doesn’t make any sense to add a probe attachment on the nose which will take away from its stealth characteristics, no matter how stealth the housing is. So it will need a regular boom just like on our KC-135s to be refueled. And the said boom is huge, requiring a passenger jet sized aircraft.
In all likelihood, a drone tanker created from Anka-3 or 4 won’t refuel Kaan in the future.
Possible drone fighters that will be made by Baykar won’t need refueling, they already have the space needed for more fuel inside. Unless the drone in question is an arsenal bird the size of a B-2, it won’t need mid air refueling.