@Jonathan *******
you need to dial in your terminology a bit, if you're just getting a 30 day free entry stamp when you show up here you aren't getting in on any tourist visa on arrival, OR visa on arrival OR even any visa at all ๐ฎ It's a free entry stamp for 30 days. AND you can extend that ONE time for 30 more days at the immigration office where you stay.
You want more time bounce out and back BY LAND <- with a service that takes you to the border and back (they have it set up so you can get out and back in without issue)
You can get two 30 day visa exempt entries (the free stamps) per year by land.