But storyboards read and merge very nicely, in my experience.
With two caveats:
- the classes section will sometimes be removed by IB. Ignore it
- the last section, inferred something (priority? segues? metrics?) with 5-6 entries, can cause the storyboard to be unopenable. So, when merging, if there are changes to that section in both versions, just delete the contents of the section.