Is my multiple re-entry permit still valid if I return before my extension expires?

My current one year extension (married to Thai) together with multiple re-entry permit will expire 26 Sept. Applied renewal today at Chaengwattana and got "under consideration" stamp with date to report back on 27 Sept. (yes, only 21 days to wait instead of 30 days).

My question is about re-entry.

As I have overseas trip planned for 12. Sep to 23 Sep I proceeded to apply single re-entry and was told I'm not going to need one because I will be back before 26 Sept meaning my old extension and the multi re-entry is still valid.

I questioned the officer and she went and checked with the boss and said no worries, just come back before 26. Sept.

Is this correct or should I expect the usual confusion and issues upon flying back in on 23rd?

Thanks in advance.

#re_entrypermit