My preference is for the latter, personally. How two or more consenting adults choose to order their lives is none of the Governments business at any level.
Any legal concerns can be handled under existing contract and probate laws quite nicely.
I would prefer marriage between one man and one woman be the only “marriage” recognized, but I agree a Constitutional Amendment would be necessary for such to pass in this absurd legal climate.
Failing that, the government getting out of the marriage business is the only other option.
Marriage is a religious rite, same as a Bar Mitzvah or Baptism, and should have no more or less legal recognition to either.