I point out that if you're trying to use per-page Weaver widgets, there is a simple solution when you're getting the error "Note: Per Page widget area: X not found. You've likely mistyped the name, haven't defined the area yet, or haven't added a widget."
When you define the per page widgets on the Weaver Admin>Advanced Options>Page Template Options page, DO NOT PUT SPACES after the commas.
It's easy to create per page widgets with a leading space, but it is not obvious elsewhere that there is a space in the name.
Based upon searches for that error message, I suspect quite a few people are encountering that problem.