I know this is an old thread but figured I'd chime in. My friend has a metal grace frame and I gave up all the stuff with the leaders and just use basic wide blue painter's tape to put on the back. I find I can get a nice straight and taut back that way. Yes, it does mean I need at least 6" extra top and bottom and prefer more. The rods on the metal grace frames have a nice deep groove along the length, I just line it up and tape away. Takes less than a minute and no sewing or unsewing.
I often turn my quilts for the borders and if anyone has info on me on how that works with the zippers, that would be great. I don't have as much access to my friend's system as I did before and the closest place I can rent a system (about half an hour away) requires the zippers... Any of the basics, like I would imagine usually you buy two zippers for top and bottom -- so can you put another set on the sides? Or do you have to take off the top/bottom first and then put them on the sides. I don't want to pay for time and get 90% complete and then have to go home change the zippers and pay for another sessions, that takes that option away for all quilts I want to turn.
My friend was given one of the kits of pre-measured heavy duty leaders when she bought her setup and we tried using them originally with varying degrees of success. I bought extra long muslin and made our own that would fit the length of the 10" frame. I made a nice neat deep (1") hem to use to safety pin the top to the muslin, or that could be sewn through with basting stitches if you wanted to take it off the machine. I also stitched cheap tape measuring strips going from center out sewn just above the deep hem, I think they were 48" inches so 8 feet, close enough to line up stuff we needed to line up.
But after all that, it's just simpler and easier for me to tape. I don't know how well the tape sticks/comes off of wood, but it's painter tape -- it should do just fine.