Sequential word repetitions in the VMS

[pfeaster]

Although I do not know both languages in which these articles are written and I see the first letters of the words in the first image as different letters, this point for me will probably be a misreading due to my not knowing these languages.

The way in which [e] was formed in the French handwriting of this period might be confusing because its two parts aren't joined.  Below I've highlighted three tokens of [e] in red to illustrate their structure.

   

Otherwise, de is a preposition equivalent to English "of" and terres is the plural of terre ("land").  In modern French, these are treated in writing as two separate words.  In Middle French, however, de was sometimes joined to the word that followed it.  This is still done conventionally today when the following word begins with a vowel, e.g., d'eau ("of water").

The first image you choose is most likely just a blank space due to a typo.
<...>
When we enlarge the words a little, we see that during the writing of one of these words written on the same page, the second letter was written by sliding over the first letter (as a handwriting mechanical error). It looks like a gap has formed as a result of this scrolling.

Here are enlarged images of those two sequences, plus three tokens of "de terre" / "deterre" without an [s] from the same document.

     

The last case strikes me as ambiguously spaced -- if it were in the Voynich Manuscript, the ZL transcription might have shown it as a "comma break."  But in the other cases, the spacing (or absence of spacing) appears to be as definite as it is anywhere in the document.

In the second image you were share, I could only read the word "mitnamen" once, but could not see the second one.

You're right that the second image contains only "mitnamen"; as I wrote, I was presenting it only to show that this unspaced form was in use and shouldn't be rejected lightly as a transcription error in the other published source I cited.  It literally means "with names" and was used in conventional legal expressions such as "we the hereinafter-mentioned with names X, Y, and Z."

However, you may think that I consider the examples you gave as successful by approaching from these rare finds. Even so, I think that few exceptions should not be compared with the frequent repetitions seen in many examples and on almost every page throughout the text.

They're not "rare finds" or a "few exceptions" -- to the contrary, they turn up constantly in documents of this kind.  I'm not eager to spend more time simply documenting their existence, so let me instead place the burden of proof on you: can you show that spacing was in fact as consistent in writings of the fifteenth century (in Italy, Germany, France, etc.) as your argument about prefixes requires it to have been?  

For my interpretation of "daiin daiin" and any other word, please pluck a photo of these repetitions from the original pages or a photo of a whole line with the meaning of the searched word. 

I wasn't looking for an interpretation of any specific case, but was just curious whether you had some alternative hypothesis about the phenomenon of spaced and unspaced pairs in general.  Of course there are tools readily available which you could use yourself to look up where cases of these appear and link them back to facsimiles.  But if you'd need to investigate the individual cases now in order to answer the question, that in itself might already answer the question -- i.e., you believe the pattern is illusory and that every apparent case of it actually has its own entirely separate explanation.  Is that much fair to say?