When i did my OA and then the OX in Australia all i had to do was attach a copy of the policy, I did not have to wait for them to put on any long stay web site, it was a requirement on the application to be submitted with the application
You are already on the visa extension, no you can not come back in on the extension. You can come back in on visa exempt 30 days if your country passport allows that or you need to do a visa run and apply for another TR60 visa before returning.
they will be busy because they were shut for Songkran plus their website crashed and so probably got heaps of inquires this week after opening Tuesday. But yes plan B is 30 days exempt and 30 days ext