Yesterday I gave HiSpec a call to see what was happening with my brakes and managed to speak to the technician who was responsible for designing my kit. He acknowledged that there had been a clear miscalculation on his part when designing this kit, which was a prototype, hence I'm the first person they've sold this to.
He explained that as a racing kit this differs somewhat from their off-the-shelf road kits as they try and ensure they provide the very lightest possible setup, with the largest disc and pad swept area, though obviously this is a balancing act. In this case it seems he had miscalcluated the PCD of the bell against the pad sweep area in trying to ensure minimal unsprung weight versus maximum pad bite.
This particular caliper allows the use of two fitments of pad and my kit was supplied with the wider of the two to give the greatest sweep area, but this had not accounted for the wide shoulders of the actual pad backing plate, as was clear from the pictures.
I was initially told that they would supply a new set of bells with their slimmer pad so as to allow more clearance, though it was then decided to machine the bell down, get it re-anodised and supply the same pads so as to retain the greatest pad sweep area. I didn't really buy this at first as it seemed like a bit of a cop-out, though if you think about it it does make sense.
He then asked me how the car was driven as he seemed to think from the pad breakdown on my DS2500s he could see they'd been pushed very hard, causing them to run too hot for the friction compound and begin break down/crumble causing blemishing. This ties in with my experience on track where I've commented before I can notice them becoming very hot from the pedal feel, though they continue to stop me and don't actually ever fade out but it's not very confidence inspiring. It seems that I may be able to cure this by running some DS3000 track pads so I've opted for a set of these once my 2500s run low. With a harsher pad it'll mean I end up eating the discs away quicker but if it gives me a firmer pedal feel and copes with the heat better then that's all I can ask for.
These are being sent back to me today so hopefully I can have the car back on the road next week