For workcation, each case is different so its hard to say. One thing they really may want to see are payroll statements for a couple of months. Anyone could get a letter from someone saying they work for the company and can work from Thailand. Maybe add a couple of months of those into the employment certification packet. For that packet, I would add a cover letter breaking down what you are giving them. I went through the LA consulate as well, but on soft power (cooking school), and got approved in less than an hour. So if you do a good job of putting your application together you could see a quick approval! Good luck!