I've reading your post carefully, and I want to share some experience with you about this. At first, I live in a country which is as flat as the world was in the middle ages (well, the people tought)- so no hills for me.
Now I drive always flat straight roads, I feel and see that my Insight has the habit to "jump" out of lean burnig, the car want to run faster, or it feels like (and it is !) you need to "floor" it to keep up with the traffic, in other words: my Insight needs a "modulating rh feet" during cruising/ steady speeds. By saying this, I define this as normal vtec-e behaviour.
As other Honda vtev-e 's are sharing this same thing, but in a less drastic way, the Insight does. In the beginning (6 years ago) I was thinking it was a "oversensitive" vtec system. Other owners reported this as well, like: my car runs faster by itself, or "it can't keep up", it's holding back, I feel the same in my Insight, it's not steady on speed and rpm's while my foot is in a steady position !!! Now I know better this is also a normal system operation.
The only thing I don't know yet is when, and at what exactly rpm the "lean-burn" mode kicks out, I estimate that this happens arround 2100 rpm's, or maybe this is an event, wich I may see as a variable.
Because of this I desperately want to built in cruise control, so my foot don't hurt anymore due to "modulating" the throttle.
As I have defined my experience, is this the same way you feel it?