I'm sorry if this has been asked but is it possible to get an ED visa for kids + Guardian visas for parents organized once already in Thailand on an STV? I know we may be required to leave Thailand and re-enter to activate the new visas. And if it is possible I assume we would need to send all our passports to whatever consulate that does the new visas?
TLDR : Answer Summary
It is not possible to change an STV (Special Tourist Visa) to an ED (Education) visa or guardian visas for parents while remaining in Thailand. You would need to leave Thailand and apply for the new visas at a consulate abroad. Additionally, it's important to consider the requirements for a Certificate of Entry (COE) and the potential quarantine regulations for both the visa application and re-entry into Thailand.