Just an FYI - I've been asked for a TM 30 notification at Chaengwattana while doing my non b extension for work. The guy next to me was also asked - he was doing an extension for his studies. Neither of us had received one, so we need to get it done and then return.
TLDR : Answer Summary
When applying for a NON-B visa extension at the Chaengwattana immigration office, it was noted that a TM30 notification is required. Both individuals present during the process were asked for this document. There were questions about the TM30 filing process, including whether it could be self-filed at the immigration office and the logistics of queuing for the necessary paperwork.