The attached rough sketch shows a trussed roof arrangement, in which on the left side, a very large overhang is such that from top of bearing wall to bottom of roof sheathing plane, the vertical distance is more than a couple feet.

We will insulate the attic with blown cellulose, and install some kind of vent chutes and heel shutoffs, where our truss heel height is 13 inches (right side bearing), but on the left side bearing, where the arrow points, why should we do anything else but pop up a “dam” of scrap materials, about 18 inches high, to contain the insulation?

I certainly don’t need any vent chutes there, because the insulation fill is so far below the roof sheathing.  Or do I?  Overhanging soffit is completely closed with finish, and will be done with a continuous perforated vent near the fascia.