What are the options for obtaining long-term visas to Thailand with a pre-existing condition and insurance challenges?

The user is from the UK and is exploring long-term visa options for Thailand due to retirement and a long-term relationship. They express concern over medical insurance after experiencing a heart attack, which complicates their ability to obtain required coverage for certain visa types. Many commenters clarify that insurance is not necessary for a NON-O visa or marriage extensions, which could be a feasible route. Suggestions were made for alternatives like Pacific Cross Health Insurance, which accommodates pre-existing conditions, as well as advice to apply for a 90-day NON-O visa without upfront insurance, and self-insurance as an option.