[aanand]

When renewing an O1, how important is it to have "new" evidence? Can an original O1 case be sufficiently strong that it doesn't especially matter how much publicly visible, groundbreaking work has been done in the time since it was granted?

[proberts]

Generally, for extensions, new evidence and arguments aren't required (although we still usually provide what's readily available such as new press). That being said, although still the exception, more and more USCIS is issuing RFEs on O-1 extensions.