Wenn Ihr in Malaysia beantragt, dann werdet ihr wohl beglaubigte Übersetzungen benötigen. Ich würde es eher riskieren es über ein Konsulat in Deutschland zu probieren - wenn ihr dort noch gemeldet seid.
First of all: unless you are US American or open a very special business via BOI, you cannot fully „own“ any business. You can own a 49% share in a business with Thai partners holding the rest. There are ways (preferential shares) to still remain in control as a minority shareholder - though gray area. Having said that: in order to legally work even for your (co-) owned company, you would need to switch to a business visa and get a work permit. But you would only get a work permit for „your“ company, if that company has 2 million baht of nominal capital and 4 Thai employees hired for every foreigner with a work permit (including yourself).
Unless you are US American or establish a special BOI company: the ration is 49% foreigner and 51% Thai. You need at least 3 people / parties. There are ways to still remain in control via preferential shares. But gray area.
Great overview. Curious: It mentions there that the DTV application must be made at the consulate or the country of (remote) employment. I am not sure that is correct. So far it seemed that the DTV application must be made from wherever the applicant is based at the time of application.