Reciprocity may force Missouri to recognize same sex unions (I won’t use the word marriage for these) formed in other states but it doesn’t require performing them in state. The first step is not forcing states to perform them.
Reciprocity is based off n equally meritorious actions, like a driver’s license or a professional license. I find it onerous to identify a same sex perversion in the same category as a heterogeneous joining of man and woman. Not the same biologically, morally or practically. Not the same. Not found in nature,only in human activity.
Didn’t say it couldn’t, wouldn’t or shouldn’t be done, only that it would be harder.