It’s all good at Antur, by that I mean it’s a hard packed quarry type surface so I’ve used HR2s, Magic Marys, Nobby Nics, DHR2s, Minion DHFs etc and never had issues with grip unless it’s very wet.
Mud isn’t an issue, the most important thing is confidence in the rubber.
Pick a decent soft compound, I tend to run my front tyre at 25psi at Antur and the rear at 30psi (28 if it’s wet), take a few tubes and enjoy…actually saying that I’ve never flatted there and I’m still running tubes, my last flat was at BPW and that’s supposedly more forgiving so work that out?!