GVilleDave, your wear is mostly at the edge... I'm wondering if you could avoid it by taking a little time to be sure the strap is pulling evenly through the DC. Also, try turning the DC upside down, so the luck runs out. You could stand to lose the luck, if you also lose the chafe!
Do you put the DC at the side of the tree, or right in the center? At the side, there is less force on the DC, and maybe less chafe on the strap.
Those are polyester straps, like mule tape, which will show wear like that. But they are very strong for the weight!
"We must, indeed, all hang together or, most assuredly, we shall all hang separately." - Ben Franklin