Not to my knowledge. It is just a design choice. The weighted flywheel means inertia from the flywheel helps the engine at low RPM when starting to move. It makes it easier to start without stalling, especially when in mud or sand, on rocks, or on a hill. They are more common on vehicles with smaller engines.In some posts mention was made of the non-weighted flywheel.
Is this a function or related characteristic of the ESS system?
I don't think they use weighted flywheels in automatics.
Here is a sales video from Centerforce clutch with a JL stock and after installing a centerforce clutch. They start rolling up a small hill until the engine stalls because the RPM got too low. After installing the centerforce clutch, the weight of the flywheel helps the jeep crawl all the way up the hill with no throttle applied.
From what I hear, this also improves the clutch feel so you can work the friction point better when starting and stopping. I have no idea how they could get the clutch feel back with a hydraulic clutch, but here is hoping.
It is all a mute point right now. From what Centerforce tells me, they can't keep up with demand and the backlog of orders is getting long.