@Rat****
the rules about 30 day extensions on 30 day visa exempt entries haven't changed <-meaning you SHOULD be able to come in on it and then apply for a 30 day extension.
Unfortunately at this time NO ONE has done it because they just started letting people in on 30 day visa exempt entries, and the people that have got in on them haven't finished quarantine yet.
So wait a few more weeks when people who have entered on 30 day visa exempt entries go to get their 30 day extensions and read the reports of them doing it
BUT the rules about getting them never changed