Well, one thing that is worth thinking about with Sani Sabik scriptures is that you have a lot more creative license than loyalists do. We basically cannot use non-PF scripture, because the TC is controlling and policing.
I would expect sanist scripture to look a lot more like pre-Nicea Christian scripture. That is, it would be fragmented and bizarre and surviving in single books or small libraries, none of which have the same content as the next. It's not like the Sani Sabik can safely have a church council to decide which books are real and which are not, after all. I mean, Omir could and probably has done something like that, but unless you are RPing specifically one of his followers, there is no reason you would follow his lead.
So how I imagine the Apocryphal scriptures is that each community is going to make those decisions for themselves based on what survived in those particular communities, and that they are going to have wildly different ideas about which texts count and which texts are more important. I would also expect that the only thing creating any illusion of a monolithic Sanist movement is the Amarr authority's tendency to label new heresies with old names.
So I would expect many Sani groups start like this: someone finds an old library with a compelling book, starts preaching it. Amarr doesn't like it, goes down the list of banned Theologies, decides that "oh, this is one of the Sanist ones." Then makes a proclamation that so and so preacher is a Sanist, at which point he probably seeks out other people labeled Sanists (if he lives long enough).
What this means for you from an OOC standpoint is that you can actively make up scripture rather than only relying on a small body of curated scripture. As long as you do not claim that *all* sani followers believe the text is sacred, you are on pretty solid ground.