What are the requirements for a Letter of Invitation for a Multiple-Entry Non-Immigrant B Visa from the Los Angeles Royal Thai Embassy?

Question about who has a good example of a recent successful template for a Letter of Invitation for a Multiple-Entry Non-Immigrant B Visa (for a consultant, not to be employed in Thailand) obtained in the USA? I believe that for the Los Angeles Royal Thai Embassy, I need from both the Thai company to be consulting with, as well as the US company I'd represent. It seems (from research, h/t Tod Tod Daniels) only the HK Embassy ever grants this kind in the SE Asian region. So hoping to coordinate this ASAP while abroad.

Also, if anyone went through the LA office as I will, how strict were they on full company disclosure documents/ examination of them. The Thai company I'm coordinating with is so large, that though they are happy to give some paperwork, they're saying the Ownership/ Board Member information is confidential and cannot be given out. The company is so large that any Thai would know it, so perhaps for a large company it's not as important with a smaller one that is announcing itself/ proving it's viable when the person applies? I am working for exact paperwork from the company, but so far, it seems it will fall a bit short in detail.... gray areas....