Here's something :O It's the first Non-Immigrant Type O-X visa I've seen issued :) They are real, they're just hard to come by due to the requirements.
TLDR : Answer Summary
The Non-Immigrant Type O-X visa is a long-stay visa that is not commonly issued due to stringent requirements. The visa allows for a stay of up to five years, but applicants must maintain specific financial conditions, such as having a minimum deposit in a Thai bank account. Discussions also highlight the annual reporting requirements to immigration, where applicants must present their financial statements and adhere to Thai laws regarding their visa status.