i run ttrs discs have done for 6000 miles now no issues
a friend has abused his ttrs discs i have seen them glowing red and he is on his 4th set of pads and done a few track days and they are still good 
TTRS disc are fine early type would warp
Dan you have 13mm front each side they must be bespoke
as i have only seen 12mm or 15mm Bizzy says 14mm is fine so what size
12mm to tight or 15mm to wide ?
nice work on your mk2 you are a busy man