I found one more thing:
currently, it is not possible to flag an edit when editing, except
when it gets flagged automatically, which makes life very complicated.
I think the most useful way would be to provide a third checkbox to
surveyors labeled "Sight edit" that allows them to sight their own
edit. This would then flag the version with the minimum requirement
for sighted. To avoid mistaked, this should only be possible when
editing the whole page, not for section edits.
Technically this could again be done like the automatied flagging:
first saving, then parsing the saved version.