That's interesting. Braking action medium to good, but the powers that be deem frozen rutts of no impact to takeoff performamce.
If it has no impact we should be using dry figures for takeoff, but MG for landing? Does it mean we can take off with 38 knots of crosswind, but only land with 29? (A320 RCAM) How about a "specially prepared winter runway" (Norway) that is covered with ice, but chemically treated, with a reported BA of good. What to do then? Land but not take off?
This stuff has been clear as mud for years. Why we can't just simplify things and use BA/Mu for both TO and landing performance I do not understand.