If this was the main concern for the Church, then they would just stop marrying people at church or in the temple. Which they already do in many countries around the world and you can now do in the US as well.
Let the members in the US get married under the authority of the land and then only go to the temple to be sealed. (Which the church is already allowing to happen.)
LGBTQ or others won’t have any legal standing to demand a sealing, since society and laws don’t see that as a valid action of any kind. No country (communist, socialist, dictators, capitalist, etc) in the world has tried to force the church to seal people together.
Maybe, just maybe it could be the Church realizes and supports people having access to basic civic rights like, jobs, housing, basic accommodations and marriage under the law of the land. That is it.