Now that I realize that there are "shared" and "per port" type of dual cord ChargePoint stations, I went today to charge at a "per port" station, to see how the MiEV's charging rate would look as it came out of the pause. It came out well, back to the full 3kW rate.
So the low rate after the pause sure does seem to be caused by an interaction with the ChargePoint Power Management sharing software.
I do not know why it took me so long to notice that there are two types of dual cord stations. I plan now to stay away from the "shared" stations, even though they are closer to my beaten path. I also do no know why ChargePoint customer support people have not clued me in to using "per port" stations instead.
Below is a picture of this morning's station display, showing that even though it is a dual cord station, it does not say "shared" in the orange text near the upper right. Below that is this morning's trace showing that the rate is 3kW even after the pause.