I bumped into someone I knew back in the UK here much to my surprise, they came on an O. They moved States but last I heard are still here.
Pretty sure they went for GC. They travelled a lot so needed a visa.
Anyway up to 3 years initially and then you can extend status in one year increments, OP mentioned Visa. And was clear in requiring specific information.
I agree with the Lawyers that O is not a clear cut dual intent like H and L. Sort of somewhere in between.