I would notarize a certify copy of the business registration, because if you don't get the visa in person, for evisa you would need to notarize it anyway. That's why I did it ahead. To have a plan b.
Indeed for evisa the contract has to be legalized also, which I didn't do.
I mean that my company was registered in HK and I signed everything digitally and they did too, so I wouldn't have a properly signed document or stamped. Even the stamp is just a logo thing.
also most officers there is Taiwanese and some Thai supervisors, so the people who actually collect your documents are locals, that's why they ask about each paper to be able to oversee before you go back at 3pm.
noone can confirm that, I think it depends on the company paper. If it's original, digital or else. The reason I legalized it because mine is fully digital and because if they wouldn't accept it , I would have to do evisa and there is the requirement is to be legalized yes or yes