The blown in insulation can be blown right over the ductwork.
Attic walkway over insulation.
Place a 2 inch by 3 inch board directly on top of the joist nearest to the edge of the attic with its largest.
Walk to one end of the attic by carefully stepping only on the wooden ceiling joists.
If you can make the walkway 2 wide it most likely would not be necessary.
Exposed floor joists can cause condensation on the inside of the ceiling peeling paint and nail rusting.
I would recommend fiberglass blown in insulation rather than cellulose because it is not conducive to insects.
If you displace insulation in order to move around in the attic don t forget to put it back as you leave.
The trail you leave in the attic can easily end up tracing a path on the ceiling below.
Work from the perimeter of the attic toward the door or hatch so that you don t trample all over the insulation you just put in.