I think a new field to the package table (not extra) is good and we can put it there on package_update/create.  I am happy we have this pull request as it is forcing me to think about this and was something I avoided because of this issue.   
I was hoping to force the re visioning to not check this new field but to be honest its probably good a new package table revision is made anyway.  So the above will be the best way if we do it this way.   Adding a field in CKAN is not too much fun even a simple one like this.