Well, after sending the sales manager at the dealership a rather strongly-worded message/rant on Tuesday, expressing my frustration with the 15+ week delay in my build, I heard back from him today. He said that my frustration was totally justified, that he agreed that the situation was unacceptable, and that he has escalated the matter to his corporate rep and to that rep's superior, to see if they can tell him why the build has been held up so long, and to see if they can do anything to expedite the build.
The sales manager did suggest that the sheer simplicity of my build may be at least partially (and ironically) to blame for this long delay, as I have suspected may be the case. Left unsaid by him, but something that I even more strongly suspect, is that Jeep is prioritizing the most expensive builds, and deprioritizing the least expensive ones. I would not be surprised to find out, hypothetically (because we will never really know), that this latter suspicion were in fact true, and were completely responsible for the situation.