The only benefits of the marriage visa is a smaller financial requirement and the ability to get a work permit. If neither are of interest stay on the retirement visa.
Just because you are a Thai tax resident it doesn’t follow that you need a TIN or to file a tax return. It just means you now come under the Thai tax jurisdiction.
individual offices may give you a little leeway but in Thai law there is no three day period to file. The law is very clear, a TM30 must be filed within 24hrs of you arriving at your address.