John C,
"we must keep in mind that we receive it as discrete photonic wave train phenomenon, not an amorphis homogeneous energy ambient state of compression."
Remember Olber's paradox, why isn't the sky filled with starlight, if light can travel forever and eventually at every point there would be a star at some distance?
Well that's what the background radiation is, not ambient radiation, but light from ever more distant sources, that has been redshifted completely off the visible spectrum, to black body radiation. The minor variations observed would be the shadows of those nearly invisible sources. The question than become why it doesn't build up over eons, to some greater temperature than 2.7k? That where the idea of the dew point seems useful, if we are looking for a cycle of expanding radiation and collapsing mass. Is there some process in the near absolute vacuum of intergalactic space that would turn radiant energy into intergalactic gases? Maybe it isn't that this energy can't get above 2.7k before 'condensing out,' but that it can't get below 2.7k, before it 'freezes out?' Obviously I don't know what the mechanics are, only that if there is a cycle, then there is some state at which the radiation expanding out from galaxies, across billions, or tens of billions of lightyears, starts the process back in the other direction, becoming some incrementally massive gas that is the initial stage of gravitational collapse. If this background radiation were from a big bang event and that event began 'everywhere,' in expanding space, then wouldn't it be largely ambient?
"We do not have anything by which to explain why light velocity is that measured value, and nothing in particular to point to in establishing a universal scale of metrics,"
If time is simply a measure of action, like temperature, then space has no dynamic or physical properties, so nothing to move, bend or bound it. This means it is inert and infinite. Remember C is the 'speed of light in a vacuum.' What is the vacuum, other than inert space? The only measured variation from C is light being slowed by some physical medium. So what provides the constant distance of unaffected C, other than space as an foundational dimensionality?
"An intersection of a greater dimension in the span of distance in space, with a lesser commensurate span of duration in the dimension of time, would induce time to extend."
If space expanded relativistically, then time would speed up/light would travel faster, in order for the speed of light remain constant to this expanded space. That means this is not relativistically expanding space. Doppler effect doesn't mean space is expanding, only that the distance in stable units is increasing. If it presumably will take longer for light to cross this space, that still assumes a constant space, as measured by the speed of light.
Regards,
John M