Can I apply for an ED Visa in Thailand with an expired letter from the Ministry of Education?

Hello! I was planning on applying for an ED Visa in Hanoi in May. The language school I have enrolled at has just called to inform me that the documents are ready, the letter from MOE expires on May 2, despite knowing that I was planning on leaving Thailand on May 6 to apply on May 7. They have said it is fine to apply on May 7 as it is only 5 days over the expiry date. Has anyone ever applied for an ED Visa with an expired letter from the Ministry of Education? Any advice?

Yes I know changing my travel dates is an option. I have already booked and paid for flights, hotel, and a pet sitter and am currently in the process of cancelling my current work permit and extension of stay to leave on May 6 so I would like to avoid this if possible.