I am sorry for the pain and discomfort that resulted from this. I truly am. I wish I knew a perfect solution (and truth be told, I wish the Pope and the Prophet would do what the Pope and the Patriarch have never succeeded at, but …). At our temple, there is an indoor waiting area, but I expect this is not universal. Many temples have a visitor center (ours doesn’t), but I know that is not universal.
It is precisely my position that the witnesses are not just “witnesses,” but are in fact participant who must be part of the faith community just as much as the Catholic priest must be part of the Catholic faith community (AND also ordained) to be involved in the marriage ceremony. The Catholic who is married (without a special dispensation from the Bishop) by a non-Catholic is not sacramentally married. The LDS should be sealed by a sealer and with witnesses who are in the faith community.
It IMO is critical for LDS and Catholics to recognize that marriage is not something two people do, but a covenantal relationship that includes God. To make changes in the LDS sealing procedures to the extent that it decreases the clarity of this truth (within a society that is RADICALLY decreasing this aspect of marriage) seems potentially unwise to me.
But, I see the perspective you offer and I have always been moved by this, just not to the point of advocating a change.
Charity, TOm