score:3
Just an update to help anyone in the future reading this -
I flew to Costa Rica over the weekend and re-entered US, making sure to give the immigration officer my passport held open to the B1/B2 Visa page and was granted 6-months no problem :D
Upvote:6
In the future, if using a visa don't hand over your passport closed, or open at the main ID page, but at the visa page.
You can exit for Canada/Mexico and re-enter, explaining the purpose for the border hop. Provided you can justify your purpose for entering on the visa, you'll be fine.