What should I expect when going to Samui Immigration for my embassy letter extension?

I am heading to Samui Immigration tomorrow to close the loop on my embassy letter extension. I was dated for return on October 11th, but was told coming on the 12th is fine. I saw some posts about people being turned away and told to come back after the 20th, but I believe most of them were coming before their actual date to return.

My questions are: 1. Has anyone here gone on their date to Samui Immigration and gotten their stamp? and 2. was there a particular time of day (morning) (afternoon) that was better?(I feel like I saw some posts in other groups about people coming in the morning and being told to come back in the afternoon for the stamp).