@Darren ********
They might be able to clarify if it's their own rule, or Thailand's policy, though. The single-most-powerful person in your travel process is the gate agent that checks you in before your first international leg. If they're not convinced, you're in trouble. So I'd try to get anything in writing that you might need regarding Thailand Pass and rules per Unvaccinated travelers. Also best if you can get an email response from the airline