Now the thing I like about Heterochony is that it is something which will put an end to the Metaphysical Era once and for all, which has been something much discussed in Continental Philosophy, but every proposal can be seen as defective in some way, and ultimately just a recapitulation of the Metaphysical in a different form. But one thing that the Metaphysical assumes is that there is only one dimension of time. So if as Dunne thought, transforming the ideas of Hinton about 4d space into an idea about the structure of time, there are multiple dimensions of time, then there is no reason that there should not be at least four of them to match the four dimensionality of spacetime so that the 3s+1t symmetry breaking that we know so well is just one possibility out of the matrix of all possible symmetry breakings of space and time with the extremes being all space or all time dimensions.
There is no proof that there is only one time dimension, and we can see that some of the experiences we have of time, like the fact it seems to expand and contract, might actually be indications that time is multi-dimensional rather than unidimensional. The problem is that we have not really thought very hard about this possibility since the time of Dunne and his Experiment in Time. Heidegger was the first to say that the temporal dimensions were equiprimordial, but he still wanted to give pride of place to the future. And I think that one of the problems is that we think of time as three dimensional too, in the sense of separating present, past and future. One of the keys I think is to recognize that the opening of the Metaphysical Era was a symmetry breaking that produced our three dimensional idea of time and that in the Mythopoietic Era time might have had four dimensions. I call the other time the Mythic, and relate it to the unreachable areas that Minkowski identifies outside the light cones. When the symmetry breaking occurred where the Mythic time was occluded then we were suddenly trapped in either linear time or circular time (eternal return). And this fundamental status has been with us all throughout the Metaphysical Era. If we see the equiprimordial moments of time as four dimensional then we can more easily see how we can mix by different symmetry breakings the various dimensions of space and time because it would be focused by the immanence of the four dimensional moment of the specious present.
I think heterochrony is an interesting hypothesis that if it was true would definitely be the death knell of the Metaphysical Era. And what is interesting about it is that it was announced by Dunne in the twenties. So everything we are calling postmodern could be the beginning of the Heterochronic Era. It is interesting that Heidegger who was determined to put an end to the Metaphsical and thought that Nietzsche was the last philosopher of the Metaphysical, and that he Heidegger was the first philosopher of the next Era might have been right but for the wrong reasons. In other words he did not pick up on the idea of Heterochrony as the decisive factor, but by defining Beyng as the dual of Being he fulfilled the requisite necessities of the transformation none the less. It was Heidegger who unleashed the multiplicity of Being. When he discovered Being crossed out he feared it was an infinite regress, and Beyng was his way to stop that regress by retracting the idea of Ontological Difference being the key to understanding Being.
A good book about this problem of the Eras is that by L. Hatab’s Myth and Philosophy: A Contest of Truths