What are the requirements for converting a marriage visa to a retirement visa in Thailand?

I have been in Thailand for 3 years now (education visa then converted to a marriage visa.)

* Currently I just keep the 400,000 baht in my bank account since when I tried to ask my immigration agent (and the Canadian consulate) I couldn't get a straight answer as to the possibility of just using my monthly foreign deposits rather than the 400K in a bank account, so at renewal time I don't know what they looked at for renewal approval ... I had both 400,000 in my account for the full year and deposits of 65,000 at least each month.

Anyway, what I would like to know is, if for some reason my marriage ends (not expecting it, but had one wife pass away on me unexpectedly already back in Canada) what are the requirements for a converting to a retirement visa?

As I already keep that 400,000 Baht in an account and don't need to touch it, is it possible that I can use the 400K in the account and the rest handled by my monthly deposits that will far more than the 34000 Baht to make up the other 400,000 Baht (but potentially less than 65,000 depending on any bills or emergencies I need to deal with in Canada?)

When reading Thai retirement visa requirements on Thai embassy sites they almost all give the option of Combination (Bank Account + Annual Income = THB 800,000)

That seems pretty clear, but as usual I don't really want to assume that this is for a type O visa, when most of these embassy sites deal with type O-A.

I assume my type O marriage will be converted to a type O retirement (or rather just left as is with new financial requirements) and that I will be able to use the 'combination' option ... but my questions is 'IS THAT A SAFE ASSUMPTION'??

Is the type O handled just like the type O-A in terms of the 'combination' financial requirements?

Thanks