Back to the OP, is it really a good idea for the state to be in charge of marriages. Remember the Othello game? If one black faced chip is at the end and you have a black chip, but all the chips between are white, you get to flip them all when you put yours down.
As the evangelical pastors of 1800s warned, the church should be the institution authorizing marriage. Sex and cohabing outside of marriage are agnostic and atheistic views of it anyway. And they don't need a state office to manage them, unless there is divorce but that seems to get managed no matter what.
But marriage is an act with God. It is a trinity. It is the belief that there are reasons beyond the visible and animal world (animals have sex and reproduce) that merit joining in God's name as an act of worship. In Catholicism it is a sacrament like communion. The wedding is a statement that there is only one kind of human sexual activity approved by the Creator of sex, and it is hopefully a statement that enough research and preparation about male-female relations has been done to say that a commitment for life can be made between that particular couple, which is also what its Creator wanted.
There is no state office that can cover this and I wouldn't want one anyway. The first thing to do after the Jun 30 SCOTUS decision was to petition local counties so that the county had NO authority re marriage, meanwhile carrying on in private with weddings and ceremonies at our churches on a need-to-know basis so that no interference is stirred up.