John,
I'll bring this to your page, and try to explain, for the nth and last time, what - to be fair - you genuinely don't seem to understand. No-one else will tell you that your ideas simply don't fit the evidence or the physics, they'll all go on letting you think the ideas could be right. Only I am boring enough to try explain it to you.
Time dilation is a single effect, described by a set of equations, and if only the observed time rate is needed, then it's just one equation. That equation works for many situations, it's very general. To explain the effect, you have to come up with a conceptual picture that works for all those situations. You can't have it fading evenly and steadily into a different explanation in some situations, and then fading back again into your original explanation on the other side. The equation shifts by degrees you see, from one situation into another. So any explanation needs to cover all situations. That's why I made the point about the two observers passing each other in the street, going in opposite directions. Each sees the other in slightly slow motion, and your explanation fails there.
Each is in fact observed with a slower metabolism than the other, because every process is observed slowed down - this may be an illusion, or each may somehow actually be slowed down from the other point of view. But citing changes to metabolism as the CAUSE of time dilation simply doesn't work.
If that was the cause, we wouldn't have pondered this for a century, it would have been very much simpler to deal with. The reason is that the mathematics would be different! And it would allow a whole range of possible explanations of that kind, but no-one even considers them, because they don't fit. Being a good mystery, it rules out a lot of intuitive explanations.
Your last post was full of errors, no-one will point them out, not even me.
Please leave this now, thanks, and good luck.
Best wishes, Jonathan