Thank you everyone for your help,

Basically this time I am trying to find out if officers at Chaengwatthana are flexible enough to extend, if I request, for a few days the "under consideration" stamp period as I need leave the country during these days for a family matter.

My current extension is valid until November 1st, they usually stamp 21 days, so that may give me a window until November 21st. Which I'm afraid is not enough.

And also, does this UC period runs from the day I will apply for a new extension or does it start on the expiration day?

I am under a Non-B extension and not married to a Thai and I plan to get a Re-entry at the airport.