I'd like to suggest a way forward on change reasons. @dr_michaelmarks' comment and @aurdipas' user story suggest that there isn't a hard requirement for question level reasons for change.
Also, there is debate about when to ask for question level reasons and what to do with multiple questions per screen. Given all this, I think we should ship the least intrusive addition first and get feedback from @dr_michaelmarks and other users.
I propose we parameterize the attribute (track-changes-reasons). We can start with the one option where we have agreement: the user will be prompted at the end of a form edit session.
@LN and I have written up a more detailed specification at track-changes-reasons spec about how this will look in the XForms spec, XLSForm, pyxform, and Collect.
We have also separated identifying the user into its standalone specification at identify-user spec as was recommended. I think this should make it easier to approve.
I would request that @TAB (especially @aurdipas, @martijnr, and @xiphware) review both these specs with the aim of revising and approving by or at our next meeting.