Possibility of Fake Drawings/Paintings and a Delayed Timeline.

[Bluetoes101]

I think I would say this sort of thinking (there's a fair few theories along these lines) doesn't account for how people dealt with taboo subjects at the time. 
What we see in the VM, if it has all these layers of secrecy, is not really something that was done.

I posted some images by a manuscript made by Michael Scot (You are not allowed to view links. Register or Login to view.) a bit ago, and within these works are details of how to perform necromancy. This was written by an ordained priest for an emperor. I believe Roger Bacon wrote of the same things, and many others. The trick was saying "If one was to do this sort of thing, which you definitely shouldn't.. but, if you were....." and that got you more of a "side eye" from the church rather than punishment. If you wrote about things in the right way you could get away with a lot. On being persecuted, even the often quoted "Spanish inquisition" were not the rampaging murderous horde that they are painted to be, most times they told you to stop doing the thing you were doing, if you refused or carried on you may incur their wrath. Here's some chat GPT, so take with a pinch of salt (below). But in general I don't think you really had to go to the lengths people think to hide things, and by going as far as the VM does (if it does) it probably makes you more suspect if anything... oh look, a book of writing we can't read full of images we don't understand.. yep seems fine!  

The Spanish Inquisition is often associated with large-scale witch hunts, but in reality it burned far fewer people for witchcraft than is commonly believed.
Here’s what historians have found:

• Witch trials in Spain were relatively rare compared to Central and Northern Europe (Germany, Switzerland, Scotland, etc.), where tens of thousands were executed.
  
• The Spanish Inquisition itself was skeptical of widespread witchcraft accusations and often intervened to stop local panic. For example, in the 1610 Logroño witch trials (Basque region), 11 people were burned, but afterward the Inquisition discouraged such prosecutions.
  
• Across its history (1478–1834), the Inquisition executed very few people for witchcraft—modern estimates suggest between 300 and 1,000 across all of Spain, with most of those coming from a few local outbreaks rather than an ongoing campaign.
  

So, while Europe as a whole saw around 40,000–60,000 executions for witchcraft, the Spanish Inquisition was responsible for only a tiny fraction of that total, and actually helped prevent mass witch hunts inside Spain after the early 1600s.