1) Actually the discussion thread from 2013 is explicitly about the "Or" affix, but it is true that as far as I know Helmut is not an acknowledged authority
2) When you first enquired about images I said that for the profiles I manage you can only get them if you are a full LDS member, which I am not.
I am now seeing if I can get one or more through some other path.
3) As I understand it the authoritative work on this subject is Minert, Roger P. “Surname Changes in Northwestern Germany.” German Genealogical Digest 16 (Spring 2000): 6-17. which I am in the process of trying to acquire, but even IF available they will not shi outside the US, so I have to arrange an intermediary.
I too very much want a definitive answer to this question, but if the explanation offered by the sources I do cite seem to fall short, they are far superior to the suggestions made in this thread.
The speculations here make no attempt to explain why, for example, this form is common in the Rhineland and Westpahalia (sometimes seen in Bohemia, but rare), and nowhere else. Every other alleged explanation should mean it would be equally common in records throughout pre-19th Cent Germany , and it isn't.
Anyway, wish me luck in hunting those things down.