In fact, I was at my local immigration office (Nonthaburi) and I asked a friend of mine who is one of the immigration officers to take a look at my daughter's visa. His response surprised me. He laughed out loud! :-) "She got this through an agency, right?" I told him that she had.
He said that it isn't a "problem" but for any extensions she would have to continue to go through the agency.
Hopefully, by the time the visa she has now is ready to expire (Oct. 2021) the borders will be open and she will have the option to go a different route. Or, maybe she will just stick with the visa agency.