One of the important consequences of ECE theory has just been uncovered in notes for UFT258, that the spin connection has a Beltrami structure, and so does the space part of the Cartan identity, and so does the spin curvature. This means that the instructive animations in recent blog postings also apply to the spin connection, meaning that spacetime itself has an intricate geometrical structure. I recommend doing a lit search of UFT papers using the box above the list of UFT papers for the Proca equation. UFT116 defines the vacuum charge current density in terms of photon mass and the vacuum four potential. This type of vacuum theory has been greatly developed by Eckardt and Lindstrom, and their papers are published in the AIAS journal and also archived in Google Scholar. In fact I recommend a lit search of UFT papers before embarking on any new work, this is plain common sense.