You say that - but are you sure other agencies won't recognize it? Can you say with certainty that it will even come up? Are you certain it's a statutory thing in Canada at all? The only references I can find on internet are that IRCC won't accept a proxy marriage
for immigration purposes. And IRCC made clear that this is for specific immigration purposes (avoiding trafficking, forced marriages, etc).
After all, a very significant number of agencies that one might deal with are provincial - and I doubt they have policies on it at all. And the feds - again, do they ever ask? I've never been asked for proof of marriage - except from IRCC. And although IRCC can decide what rules it uses and what marriages it accepts
for immigration purposes, it has no ability to tell others what is a legal marriage or not. Reminder: at heart this is a
provincial responsibility.
Sure, it might get wonky if one ever had to go to court eg divorce and demonstrate things - or some things possibly where benefits matter (but if couple living together, kids, then not sure there's any difference). For death benefits and effective management of a will, perhaps. But I repeat: I have no confidence ANY of them will care about this or even be aware of the issue, if there's a marriage certificate that's facially valid and no-one contesting. And in courts, well, I leave it up to the lawyers to comment - but I don't think there would be a clean 'you may have thought you were married but you aren't because of this technical issue from a decade ago' decision.
Even more so when the standard common-law doctrine applies: a marriage valid elsewhere is valid here, unless contradicting basic tenets of Canadian law. (And I don't think proxy marriages pass that test, since proxy marriages historically have been recognized.)
So say what you like: I doubt it's as cut and dry as you think. I'm disappointed I didn't think of the conjugal route for those in this situation, sicne divorce and remarriage often isn't realistic.
The proviso being that I have a strong suspicion that IRCC would NOT accept such cases where the proxy marriage was for arranged marriages, nor for cases where any hint that it's not a genuine relationship, and extra scrutiny of some things like large age differences, etc., - because those overlap with the reasons IRCC enacted the proxy marriage policy in the first place. So it's not a panacea.
And a warning for anyone who succeeds in this: while I don't agree with
@canuck78's assumption that lots of other agencies won't accept it, there ARE potential legal risks, and I'd strongly suggest a consultation with a lawyer. It's possible that the most prominent risks can be dealt with using a marriage contract (post-nup) and a well-written will and testament, as you really don't want to leave your spouse in a situation without clear title to joint assets (and where the estate is, what's that called, intestate AND the marriage could be legally unrecognized.)
But I think the basic answer - as above - is that it's only IRCC that has this rule.
