Well, pretty simple, the way that works is that Russia refrains from heavy bombardments close to visiting dignitaries. Knocking off a NATO country PM or something like that would not go over well.
Even with Norway's donation, I'd be surprised if Ukraine actually received over 30 ready-to-go F16's by the end of 2024. Trained pilots won't be the problem.
Granted, that could change if other countries retiring fighter jets chime in. The US certainly has plenty to dispose of.
For this to be, there would have to be back-channel communications between combatants. Is that your assertion?
Were that true, between US and European elite, there could be every day a state or celebrity visit. Better cover than actual air defense.....