It sounds like a good idea, the only problem is that formation would have to be broken every time IMC was entered, and collision avoidance would become a bigger concern.
Also, what if one of the planes has a problem ? what he īs leaving a contrail behind ? what if he has to descend rapidly...Communication would go from the 5th or so step in the memory items to the 2nd one.
I donīt know...lotsa testing I guess before bringing 200 pax/million dollar planes within half a mile apart, I guess.
Good luck guys !!