@Sean ********
You can still get the multiple entry 'O' visa, but you have to have, in their opinion a good reason for them to grant it. This is a copy & paste from Thai Embassy, London and is not refernce to retirement.
1. Passport or travel document with validity, not less than 6 months, and at least 2 blank pages
2. Your recent photo (selfie is acceptable)
3 Declaration form
4. Financial evidence showing savings of not less than £10,000 for a multiple entry visa, or a monthly state pension of £650. Please show the most recent statement
5. Proof of residency e.g. council tax bills, driving license
6. Travel history in the last 1 year- please upload a page of your passport with a visa stamp, or a blank page if not travelled in the past year
7. Photo of the applicant holding his/her passport
8. Your flight and accommodation (hotel booking for the first few days will be acceptable) details
please ignore Health Insurance on the E-visa system for all Non - Immigrant visa O