How sure are you that 40 bits is a good number of bits? What's your justification? It takes over 30 years to deploy new bits, so you have to be really sure before you start that effort.
> It takes over 30 years
Only because it is overengineered. Parents pragmatic protocol would have been adopted faster
40 bits would've bought us a lot of time and would've kicked the can down the road several decades. People from the future would be much better equipped to design a new protocol because they understand their needs better.