Why don't skillbooks dissapear after use?

[thiosk]

I'm working on a literature mod and one of the peskier problems i'm having with basic functionality is that the books dissappear after use.

 

My desired functionality is: 

a, Book delivers benefit per page

b. book stays in inventory when finished (like a skillbook).

 

Its quite confusing sorting out how pz decides whether to consume the item in question or not.

as before, the skillbooks do not have the replace on use (self) feature. 

 

Now i can go through and addkey addval pairs with replace on use and item.name, but this is time consuming. My real question here is why the skill books aren't consumed and can I take advantage of that mechanism instead?