i got this question by private message:
The modus operandi of the new workplace is a 3 month probation period during which staff who are hired from overseas work on a tourist visa. After the probation period ends, documents are provided to apply for a non-B visa, as well as a work permit. Being a long-term resident in Thailand already, and married to a Thai, it's needless to say I can't take the risk of working on the wrong visa.
it seems that my point of view is different, I would say do not work without a visa that allows you to work with a work permit and that work permit in your pocket.
Text on the visa is Employment prohibited (picture 1)
Text signed by visa applicant (picture 2)