The company I work for writes in English and so far my husband has had no problem getting his dependent multiple entry non o visa from both penang, kota bahru and London.
I did a boarder bounce in July (but not with andaman club, took a private long-tail) without any problems. One with b visa and w/p, two with non o visas
I am not saying you are not right about the overstay fine, but I have friends with work permit and a child born in Thailand and the last time they came back from Malaysia (I am not sure about what boarder crossing but they came by car) and the immigration officer stamped the child's passport saying that visa needed next time. This happened in December 2017
Well since you have very different experiences, maybe one of you can tell me if I need to show 400.000 in Thai bank account for each of them or only my husband 😂