@Jo *******
That is not something you should count on anymore. That used to be possible before Covid, but not since. They started cracking down years ago, and since they changed visa exempt to 60 days they've been VERY strict. Many people who have entered and gotten a 30-day extension then left have been pulled out of line at the airport and interrogated after only their 2nd entry, and told to get a long-term visa or be denied entry next time.
Just because there is no rule does not mean it's unlimited.