At the Chiang Rai office, I took copies of my TM30, passport bio page & stamp, visa, lease agreement, and completed the COR request form. I was given a ticket to wait 7 days, and when I went back it was given to me with no issue. This was two months ago.
Anonymous participant I like using Agoda and have done cancellations before with no issue. Some options you are charged right before you check in and others you can get refunded, as long as it's refundable. I'm sure there are other good ones too. Best to you. Blessings ☺️
Anonymous participant you can book a refundable hotel on Agoda and make sure to book a flight that allows you to make a change to push the date out. For US - Washington, it took a total of 15 days. I'm not sure where you're located, but I'd give myself at least 3 weeks for visa application processing. The anticipated arrival date doesn't have to be exact either.