I found another "poxleber"

[Koen G]

Forgive me if this is already known, it can sometimes be difficult to keep up with everything discovered on the forum here. The curated thread says x is uncommon in medieval German manuscripts, but it seems it was not to unusual for it to appear in place of the consonant sequence /ks/

Yeah don't worry about things being already known, this is notoriously difficult to follow in online discussions that span literal decades

In this case, I had already looked into that, but drawn different conclusions: You are not allowed to view links. Register or Login to view.

Basically, for German MSS, these are the possibilities, from most common to least:

1. The majority of German MSS either contains no "x", or only in Roman numerals.
   
2. "x" only in numerals and Latin words/lines/sections
   
3. (getting rarer) "x" in a number of fixed spellings. These are the ones you also found: wax, flux, wexel...
   
4. Very rare relative to the others: "spontaneous" replacement of "ks" by "x"
   

In short, there are some words like wax, where the "x" is seen as the standard spelling. But replacing "ks" with "x" elsewhere is generally not done. Freedom of spelling in the Middle Ages doesn't mean that there were no customs, and randomly introducing x was not customary in MHG.

Note that what happens in the VM is even one step further, because you're not just replacing part of the root word with "x", you are including the genitive -s. This would be as if in English you'd write "Rick's book" as "Rix book". Or "the bank's money" as "the banx money". 

If you can find cases where genitive "cks" is written with "x", those would be more relevant. When I looked for them many years ago, I found only one. A shipment of bacon (speck) where the genitive form was written as "spex". 


About the mich with superscript "l", that's an interesting one - I guess you caught someone misspelling "milch" and then correcting it?