What's the clutch rated at for the manual ?
No idea, but I would imagine it's more resilient than the DSG version - less to go wrong with it at least. I'm sure i've read somewhere that the DSG is rated for 450Nm
It would be interesting to see if the GTD manual has the same clutch build as the 204PS 3.0TDI manual with 450Nm - Tiptronic goes up to 245PS (580Nm) in the A5/A6/A7, but the manual doesn't. I wonder if that's down to Audi thinking that everyone driving the exec range of their cars will want a DSG or limits of the manual clutch (plus whatever % overbuild they add in for assured longevity). If the GTD does have the same clutch as the 3.0 204PS version, then you're only asking an extra 11% from stock rating to get 500Nm.
When you look around on the net, it seems Fiat/Alfa are the biggest for reported clutch slippage when fitted with tuning boxes, and there aren't exactly many of those examples. With VAG having a far bigger range of engine outputs above 150PS in the diesel range than Fiat group, are they more or less likely to have a few heavy duty clutches to suit most of the range rather than one per output for the 170/177/184/190 2.0TDI and the 204PS 3.0TDI?
How you treat your clutch normally will have a big part to play in the longevity even without adding a box. Ride that clutch at junctions (maybe less of an issue for some who used to before autohold) and you'll be lucky to see 50k miles from it. Treat a clutch nicely and no reason you couldn't see 200k miles out of some of them (with stock power, admittedly).
I haven't seen any clutch slip yet, accelerating hard up a steep hill for 1/2 a mile. Delivery of the power is probably a big factor too, progressive development of the power has to be easier on the relevant parts than going from a nothing to everything development. I don't push into the clicky part of the accelerator generally, it just feels so un-natural to do so.
Looking at Andrew's latest 3+1 Dyno, when you reach 200PS output, torque curve dips to 485Nm max, and the torque really starts to tail off above 225PS output/3500rpm. You'll not be pushing the full 500Nm for long when you floor it.
