XLSForm Offline 1.4.0 ODK Validation errors

That would be a nice feature for sure! I've filed it at https://github.com/opendatakit/xlsform-offline/issues/13. This would be a nice contribution for someone who knows a little bit of Python.

Until that feature ships, you can always watch the releases category and you'll be notified automagically when there is a release for any ODK tool.