This seems like they are advising you about applying for a marriage visa. Have you asked them for their list of requirements for the non o retirement visa.
It's usually very straightforward with no agent required.
I have always used Wise, but your post made me thing at a bit of a tangent.
If you used your home bank account to transfer via Swift for a large sum, would that alert them to the fact you have moved to Thailand (I ask because banks sometimes close accounts if they realise you are living abroad).
Using Wise is more 'discreet' imo, even if it costs a few Baht more.