I have used the 2.8 with the garda hitch and it did start to tear the cover. I have used the garda hitch on larger diameters without any problems. I have gone back to just using one lightweight biner set up like the pic below.
The line going up just loops thru the huggers and back down. To adjust just place one hand below biner and take pressure off and pull up or down. Takes about a second. With some biners it is easier to wrap the cord on the back spline. I have used this system more than anyother over the years.
The little bit of white showing thru the cover on the cord wrapped around the biner was were the garda hitch started tearing that cover