Great read. I agree with much of your observations and feel that the evaluative categories of the five necessities et al have been overrepresented in Maqasid discourse for a number of reasons. I also feel that there is a theological explanation to many of these positions, given that those who have theorized the five-part categorization for the most part have been Ashari scholars, who theologically are most famous for occasionalism and their denial of ta'līl. Those scholars have mainly been from the Shafi and Maliki schools. Maturidi and Athari scholarship I believe approaches the issue very differently and you have identified much of that, simply because they do not deny ta'līl. There are less in need of an abstract to explain the purposes of the law because the law itself in every instance is purposeful.

There's a lot more that could probably set about this topic but I think that your article here is a good start for theorizing how Hanafi / Maturidi scholars envisioned the Maqasid genre differently than what it has typically been characterized as.