@MStarmer - Since buying the fancier scan tool, I can definitely tell you in Normal (and assuming Eco) drive mode, Honda's VCM system is
constantly switching off the rear bank of cylinders, even at speeds lower than 30mph and within a minute or two after starting driving. I believe this may be leading to the higher amount of carbon I'm seeing when cutting open the oil filter. It most certainly isn't helping the engine, as Honda has to use active engine mounts to help counter the imbalance caused when switching off the rear cylinder bank.
Using the scan tool, my testing so far shows drive modes Sport and Tow prevent the VCM system from activating. In addition to keeping all cylinders active, both of these modes automatically turn off the auto start/stop feature (this part is stated in the manual). Tow drive mode holds the gears slightly longer than Normal drive mode, but not much. Also in Tow, there's slightly more engine braking. Sport drive mode holds the gears much longer and provides significantly more engine braking. So now when my wife and I get in the car, instead of immediately mashing the start/stop button to turn it off, we change drive modes. My wife prefers Sport while I use Tow. Know that in Tow mode, the rear sensors are disabled from automatically braking if you're about run into an object. The rear camera still operates as normal.