Arasaka endings are invho, fucked.that could actually work for most of the endings, but not all of them
The other 5 endings can all branch back together.
Legendary V wants to return to NC after Crystal Palace.
Nomad-ending V does not want to come back to NC but does not want to die either.
Engram-V wakes up in an new body in NC, after alt decided to get V on a mission that requires a body and to finally fulfill her side of the deal.
Greeted by V's old body and Johnny, who made it possible.
In all possible new openings, alt and Johnny could take a large role.