When something that is clearly wrong is described here as "alternative", a lot of people just don't feel like participating at all. It's like talking to a wall.you don't participate in alternative ideas,

Has the "cause" changed since Newton's time, or has the explanation simply been updated to account for relativistic effects between frames at different potentials?and I guess it was a surprised to see you don't believe in the modern interpretation of GR re. the cause of gravitation.

My view is that math is generally either right or wrong. Since Poincare and Lorentz produced the math which correctly described relativistic observations (see Fitzeau) as the projection of a rotation onto the observation plane, and it's obviously right, then the application of that relationship to the newer tensor notation of GR is kind of anti-climactic. But it takes years of training to understand the math of basic physics, much less the higher math. That means novices won't have a clue whether it's any good or not. I doubt if they will understand the simpler Lorentz rotation.My view is that the math is nearly perfect,

No. Mechanics divides into two to scenarios: statics and dynamics. It's almost entirely devoted to Newtonian physics, usually solving for force, velocity, power and energy in machines and natural systems. The term "energy density mechanics" is meaningless to that branch of science. Besides, the "how" has more to do with the projection of a rotation than anything. So I continue to doubt that novices have a handle on the "how" since they haven't gotten past the more elementary math of linear algebra & calculus, much less trig & geometry.but there are energy density mechanics at work to explain the "how".

Not really. Mass causes spacetime curvature, so you're back to the Newtonian explanation with the same answer: gravity is "caused by" mass.Since curved spacetime is the GR explanation of how gravity works,

That seems awfully contrived. You sound like you're looking for confirmation of something you hope to be true.and the EFEs quantify the curvature to predict the geodesics that objects follow through spacetime,

And there it is. Of course "interchangeability" is meaningless here. You left out the most essential rule: that gravity arises from mass. Nothing is going to be "interchangeable" about that. Mass is (fortunately) amazingly stable.gravitational energy and the curvature might be interchangeable.

Of course the simplest idea to take home from this is that this is a very old, heavily trodden area of science. The odds that an expert can conjure up something that isn't already well understood are slim to none. The odds that a novice can do it are nil. That's why no one really cares about claims that "mainstream science" is fundamentally broken, or missing the boat. Worse, it's preposterous to assume so without first mastering the principles in question. In fact, the invention of obscure jargon to pretend that Nature works differently than already known is quickly seen as a cynical attempt to discredit science the novice never bothered to learn, at a very shallow level, one that equates with trying to trump sensible basic explanations with nonsense.

Why bother? Why not just engage the dialogue at the last level mastered in school? At least there there is hope of being reasonably accurate.