Thanks for help. Your answer about via in that post is really useful. I’ll try to make a PCB to test and verify. And the parts about how to cook a PCB are also good opinions. I’ll think over them.
However I still have a problem. If I put a pad instead a via on a thermal pad, all copper layers, how to make the B.Cu coverd by solder mask like a via? Just tick the B.Mask?