However, I opened a Krungsri account today with passport, non-o extension stamp, cell phone bill digital copy sent to bank email, TM-30 digital copy sent to bank email.
really? Are you stating that he does not need to apply for another 12 month extension of stay to start again November 20, 2025?
It is my understanding that he will get stamped in up to his current visa extension date subject to have the required insurance through that period.
Multi-entry simply means one can exit and enter multiple times during the extension period without purchasing separate exit stamps each time. TM-47 reporting is reset to 90 days at each reentry.