From all that, I gather that your answer is "yes", that you do believe
that the current in a small inductor with close turn spacing (i.e., one
where the fields from the turns couple well) flows around and around
along the wire at near the speed of light, resulting in a delay from end
to end approximately equal to the wire length divided by the speed of light.

Or did I misinterpret what you said, and you don't believe this?

Roy Lewallen, W7EL

Richard Harrison wrote:
Roy, W7EL wrote:
"I maintain there`s no such group as "other coils", but that coils act
quite differently depending on their physical sizes and the amount of
coupling between turns."

I wrote:
"That`s how the experts say the coil in a TWT works, and is no different
from other coils."

All coils aren`t inside TWTs, but all coils do create inductance.
. . .