@Bart *************
last year we didn't get back in time to renew my Non-O extension, had to come in on visa exemption and start the process again when we returned.
Upon arrival I got dragged out of line and grilled for a good 15-20 mins, the entire time I spoke only Thai, when I asked why I was 'chosen' to be questioned at the end the supervising IO said 'your study visa', when I double checked and asked if that was the only reason I was told yes.
Logic would make one believe it would help, I certainly thought it would too, but from my direct experience last year, it doesn't make any difference. (I will add though, the conversation went from very serious to quite relaxed and lighthearted when she noticed I could actually speak Thai but I was still being asked about my attendance, the location of the school, my teachers names, how long and how often class was, if immigration showed up, etc etc)