A Non-O Visa Based on Being Over 50 does not need to be acquired in a person's country of passport. However, some Thai consulates does not allow a non-resident to apply for visas.
A Non-OA Visa Based on Being Over 50 MUST be acquired in the person's country of passport (or potentially if they have long-term residency status, if that country also sells the Non-OA visa).
Not true. A Non-O visa based on being over 50 does not need to be acquired in the country of residency or country of passport. In Pre-COVID-19 days, people would border bounce to Vientiane to get new Non-O visas based on being over 50 frequently.
The problem with a Non-O Multiple Entry visa is that border bouncing is very difficult, and not a viable plan as of right now. I don't know if the consulate is selling that specific Non-O visa right now either.
1. The Non-O Visa based on being over 50 is NOT multiple entry. This visa allows you to stay in Thailand for 90 days, and allows one entry. If you want to leave Thailand and return, you will need to get a re-entry permit, which keeps your "admitted to" stamp "alive" when you leave. This visa is cheaper to acquire at the local consultant, and *MIGHT NOT* require a police report or special health insurance.
2. The Non-OA visa based on being over 50 *IS* multiple entry. On each entry, you are stamped in for one year, or the length of your health insurance, whichever one is less. This requires more paperwork including a criminal background check, must be issued from the Thai consulate of your passport (i.e. if you're holding a British passport, the Thai consulate of London), and requires medical insurance. IF you acquire a One Year Extension of Stay based on being over 50, you will need health insurance.