Can't help with moveable markers - I actually use fixed markers at 10, 15, 20 & 25 feet on my Type 5 and Type 7 full sink lines. A single orange at 10 ft; single white at 15 ft; two orange at 20 ft; two white at 25 ft. This YouTube video shows how to whip finish onto the line. I make the markers with two layers of thread, 1/2 to 3/4 in long and covered them with UV epoxy.
Fixed hang markers
I would then use one of my guides in conjunction with one of the markers as a reference point. Since the markers were 5 ft apart, there is always 1 marker somewhere in the guides of my 9 ft rod. The fixed markers really helped improved the consistency of casting the full sinking lines for trolling as well since I could always cast with the same amount of line out the end of the rod.
Ken