Unless they're fully floating discs, I wouldn't bother.
Because of the way Alcon's bobbins are designed, I can see from the marks they leave in the bells' powder coating the discs grow by 4-6mm in diameter when hot. It's because of the floating technology and quality of materials, they don't do what is pictured below.... which will happen to non floating or crap discs if you hammer them on track.
If you just want them for the road, ask yourself why you need them??
Saving weight. Do the wishbones/hubs instead as these are permanent.
Asthetics. Rotors that look nice costing say £300 each time they need replacing (which may be more often than you account for, if the grade of metal is poor) doesn't make sense.
Performance. You'll see no benefit. Pads, fluid and the clamping force of the caliper are the variables to play with. Get some really hard pads and just accept you'll be ruining £80 OEM discs twice as often, or invest your £400 in some decent calipers which again are permanent.