Hoping someone can help clarify the transit rules under the current Thailand Pass scheme.

MH decided to terminate HKT service until 3/28, meaning our flight next week is now canceled (thanks for the advanced notice... ) We now need to find another way out of Thailand, and the only realistic option appears to be a flight from BKK. We're entering under a Sandbox approval, staying only 5 days. The Thailand Pass website now seems to imply that we can travel to BKK for the purpose of leaving the country (5.3 If I stay in Thailand for no more than 7 days, I will not be allowed to continue to other parts of Thailand beside the Sandbox area, except for departure out of Thailand.) Has anyone successfully boarded a domestic flight for this purpose? I doubt TG will allow us on the the sealed route TG2750 if we're not continuing out of the country on a single ticket with their airline.

In case transit is not allowed under the Sandbox approval, should I try to apply for Test and Go instead? Strangely, the testing and hotel requirements seem to be identical, but Test and Go allows more flexibility.

Thanks for the assistance.