Blazer vane rest clearance
Here is a video on YouTube that shows how to install properly:
I did take off the top keeper bar on my Switchback because the screw that held it on kept loosening up. You really don't need that top keeper bar so you could just take that off.
Otherwise you could put a couple washers under the keeper bar to raise it up a bit. I always shot cock vane up and had more than enough clearence.
I also set mine up so it doesn't come up until the last 1/2 to 3/4 inch of draw cycle.
Have you ever set one up with Blazer vanes? This is more of an issue caused by the vanes than the rest. I took a picture while I was sitting in a blind to show the issue, but I don't know if it helps. In person, you can see it by sighting down the back of the arrow, but I could not get a picture to show anything from that side. Anyway, in the picture, the cock vane is up and you can see that the tip of the cock vane will nick the arrow keeper as it flies by. The rest is a code red.
though i never had a problem with the 3 I setup up for people, I always had them timed perfect and shot cock vane up...always used hooker red lipstic to confirm no contact, and always used a Simms shelf pad under the launcher arm to cushion the blow..ripcords have also been known to break launcher arms from hittin the shelf,