I've read over a few of Mathis' papers. I do enjoy the way he thinks... by that, I mean he actually
thinks, and does not just regurgitate the accepted science line, much like Larson.
And you are right--there are a lot of conceptual parallels between Mathis' and Larson's work, particularly concerning the concept of
change (motion) being the basis of all measure, and the
point (what Larson calls an "absolute location" to avoid giving dimensions to a dimensionless point). There are some radical differences on the concept of
time, however, which is to be expected. To the best of my knowledge, Larson's 3D time (Cosmic sector) was only ever considered by Hermeticists, never physicists--they prefer antimatter (but consider it to be oppositely-charged space, not coordinate time).
From what I was able to grasp, Mathis considers "time" (
clock time, as used in RS/RS2), as another spatial vector, so he retains a vector as δx/δt (both components vectors). In the RS, time is just "inverse space", so it has all the same properties of space. Larson always held that the vectorial nature of time could
not be vectorial in space--it had to appear as a net displacement, a scalar (crossing the unit boundary--the inverse--would remove coordinate information). It may be that temporal vectors CAN transpose to spatial vectors; it is something to consider. (Since we know lines of force come from time, not space, a study of electric and magnetic fields should reveal the nature of the vectorial transposition, if any).
I read his paper on "Infinity Calculus" last night--most interesting. I was just discussing a similar concept with Gopi a couple days ago, concerning
infinitesimals (from a paper Gopi wrote on the topic). I'm not a physicist nor mathematician; I build things, and in construction, you realize that there is a BIG difference between blueprints and reality. Mathis points this out in
his paper on Calculus, though calling it "diagrammed" versus "physical." In construction, you have to deal with tolerances--you can only approximate measurements, down to a specific precision, determined by the tools involved. Mathis took a similar approach with Calculus, stating that you cannot go to zero or infinity (what would be the "perfect" measurement), because nature doesn't do that--it also has tolerances, what Larson calls "discrete units" or the quantum of QED. His paper goes through a historical perspective on where Calculus came from, and where people have misinterpreted the mathematical conclusions concerning the differential. His "unity" approach to the differential fits in very nicely with the Reciprocal System and its "unit datum."
Most of his papers concern SR and QED, so I'm a bit lost there. But, I can easily see how to adapt his system of Calculus to RS2, so I'm going to give it a shot to see what that turns up--when time is considered as a 3D inverse of space, in the context of his conclusions.