@morgan_j - we configured 1.3 side by side with 1.1 on the Canvas test instance to confirm functionality and to determine how we wanted to proceed. Once 1.3 proved to be fine we then removed 1.1 from Canvas Prod (though we considered leaving it, rename it 'old zoom' and hide it via CSS), but thankfully we were trusted that 1.3 was working fine and we removed it from Canvas. We made the change between terms and it has been working fine since that time which was perhaps three years now.
There was also an update to the LTI Pro that we found useful and 1.3 was needed for that. So yes, I think 1.3 good to go.
As for gotchas - I do not recall there being any. Zoom just works.