CO-CO
Rather wrinkly & occasionally cantankerous member
The vast majority of farangs like to take their wives/girlfriends with them when dealing with anything official. Whilst the visit is in connection with the farang alone, he is invariably sidelined, and the entire conversation is in Thai between the officialdom and the wife/girlfriend.
I have learnt a modicum of Thai in my time here (not always correct but usually sufficient to get things done), and invariably deal with things myself. With one problem concerning the spelling of my daughters name. I attended the Buriram amphur to correct the birth certiificate, and the Prakhonchai amphur to correct the tabien baan (House reg book). I fended off requests for my wife to come along, stating that as the Father I could and would deal with the matter alone. They accepted and it was all smiles later.
That is fine and I would prefer to operate that way with general officialdom.
With respect, your immigration is somewhat different to EVERYONE on here and you do not experience the unnecessary clamour by immigration to include the 'wife' in the process. I am not married, a wife/partner should not be needed to apply for an extension based on retirement (Coffee is an excellent example of this and I hope he finds time to post his experience) and they should certainly NOT be required to sign anything.
The fact is they are, and in this case it is a comfort blanket for Thai immigration and not the usual (wife's presence) comfort blanket for the Farang. With immigration the wives usually speak when spoken to and the situation does not deteriorate into a 2 Thais vs 1 Farang position as happens with many commercial transactions.
I did hear about one case of a Thai lady who vociferously put her point across that her 'husband' (by virtue of a village wedding) was entitled to an extension based on marriage and no proof of money was required.
I understand that she was quickly put in her place and escorted off the premises.