My Solution – Abbreviated Middle High German

[ololololo]

I'm looking for something similar in German.

I can recommend here the Cod. Pal. Germ. 213 as an example, which in my opinion has many parallels to the VM.
Many words are abbreviated into this manuscript. However, to a usual extent, since this text should remain readable for everyone.
Nevertheless, the examples show that thinking in abbreviations was normal and did not hinder fluent reading for the experienced reader.

You are not allowed to view links. Register or Login to view.

It's not a new thing that medieval authors used abbreviations. They could shorten every word if it wasn't small enough.
Of course, internally, your theory is consistent, but Voynich's manuscript doesn't really seem like someone's "prank" or "creative idea of a shortened language." And yet... why this particular way? Why not, for example, shorten all words to a single letter? Why create new alphabet?