If it is legal.
I don't see how all this game playing changes anything, either the relationship will comply with the law for recognition, or it won't.
That was the way it was in 1950, and 1900, and 1990, either you do what the law requires for the government to recognize the union, or you blow off the government part.
we USED to have common law marriage when the frontier was open and recording was difficult.
When recording was “voluntary” it was rife with fraud. Consider divorce. Divorce is because you say you are divorced and there is no obligation to childsupport or even standing to subpoena for testing. It is a leftists wet dream.