I just recently received my 10 year LTR. My original visa entering Thailand was O-A. No hassles at all. The folks at BOI are very helpful. Questions submitted on their contact form are answered very quickly. I had some questions that I preferred to ask in person. Checked in at their front desk and two counselors came to sit with me and answer questions for about 30 minutes. Very helpful. One thing to remember, this is a very professional office and if you do visit, shoes or sneakers but no sandals or similar, a nice collared shirt (I wore a tie), and long pants. The people at BOI want to see you get the LTR so go for it!