Thanks for sharing that.... How do you think timings differ across different seasons? For example, in the summer, I'm sure your observations are probably very reflective. What about in the fall with a few layers? Now how about the winter with multiple layers?
Layers certainly can complicate things, and I've found that some are more restrictive than others. Generally speaking, I find that IWB and pocket carry in the front pants pocket are similarly effected. If the layers don't obstruct access to the pocket, they usually aren't much of a problem for IWB access either.
Now, there might be speed advantage to carrying in the pocket of the outer layer, but I generally don't like to carry like that (it complicates situations where I might need to remove that layer) so I've never tried it against the clock.