gbp requirement, or proof of a state pension. As the OP is of pensionable age, is this not an option??
“Non-Immigrant Type O (Retirement (pensioner aged 50 or above with a state pension who wants to stay in Thailand for no longer than 90 days) - single entry only)
Financial evidence e.g. A copy of pension statement if the applicant is a pensioner, or a copy of 1-month bank statement showing your income from pension, or 3-month bank statement of at least £10,000
Confirmation of legal residence in the UK or Ireland”
why not try and do it online at the earliest possible time and see if you get confirmation through before the last day you could go in person. If it goes through you’ve saved a trip, and all future trips. If not, well, you’ve lost nothing.
(Im not sure of the time constraints involved when reporting online vs in person)
Whats the issue with getting your home insurance company to complete the silly form? Is this being refused? Obviously the directors signature isnt gonna happen, but how would that be checked anyway..? Get a helpdesk agent to fill it in, and their direct boss - doesnt seem too hard 🤷♂️