Since the build I had used exhaust wrap around the tailpipe to cushion it & the silencer against the rear bracket.
I have stock GBS silencer with Cat and the bracketry.
Heat wrap generally lasted about 500 miles or so before looking like the left of this picture - its not so much heat damage as the silencer needing to move and wearing through it.
I selected two materials for an oven test to gas mark 8/220Âșc (while my wife was out :) ). Rubber windscreen surround & an off-cut of silicone cooling system pipe.
The windscreen rubber bubbled and perished within about 30 seconds, the silicone pipe didn't seem to mind at all even after 5-10 minutes and maintained its rubber properties; some question over its abrasion proof properties though.
However...
After some chat online, Paul recommended using an off-cut of fuel pipe.
I tried this for the run out to Castle Combe this weekend, approx. 300 miles round trip of mixed driving.
Looks like a contender, the picture is after 300 miles - mostly abrasion marks either side and some evidence of heat getting to it - but still in good condition - certainly better than using exhaust wrap; so this stays on until I find something better.
I just cut the length to sit over the bracket itself, over the top is the normal spring clip.
Update - Added a short length of exhaust wrap over the top, under the spring too, just stops excessive rattle when driving.