I agree but think it might be too hard for UA to verify (to prevent selling the benefit on eBay).

That does raise a related question, though: does the MM spousal benefit extend only to your wedded spouse (e.g. does UA ask for a copy of marriage license under some circumstances), or can it be extended to spouse-like persons (civil partners, long-term relationship partners, etc.), like the RCC spouse membership used to be? (That did require extra paperwork IIRC.)