@Doug *********
if you have a 30 day visa exemption stamp, in normal circumstances you can extend it for a further 30 days, not just 7 days.
Normally short extensions for 7 days are given to keep you legal if your return flight is a few days after the exemption expiry date.
Also, you’d be here legally if you have a 30 day exemption OR an extension to such exemption so I’m not really sure what you mean.