Personally I don't think facing the BB shell is critical at this point as with the amount of thread locker present I haven't yet torqued down the cups to 35Nm.
Which I believe is not necessary as the friction of a Loctite's 222 thread locking compound is 26Nm and the dry thread locker Campa is using is pretty similar.
It would matter if you'd want to torque the cups down as this force would actually act on the threads of the BB shell and cups and force them into a certain direction.
Either way, as my BB shell measures 68mm spot on several points I think I can safely assume it has been faced before. Campa's tolerance then also allows me to actually back of the cups a bit, to the point of just not touching the BB shell and still fall within tolerance, I suppose.
What I do suspect however is a very slight run out of the coaxiality of the threads of the BB shell. Not so much so you would actually notice it when using the good old ISO tapered BB yet too much for the outboard bearings to actually work as they should.
It must be rather slight as I never suffered excessive bearing use or drag whilst using old style BBs with this frame.
BTW, none of the threads inside the BB shell are damaged but I think it wouldn't be a bad idea to chase them and if necessary recut them properly so they are perfectly coaxial for I fear that's where my problem stems from.
I also se anti seize on BB threads even if threadlocker is present. If the shell is not faced it may or may not make a difference. It is standard practice to face the BB shell prior to first install of external cup BB. It helps bearing life.
May I ask, why use both thread locker and anti-seize together? The presence of anti-seize negates the presence of the thread locker.
Thread locker is an anti-seize which acts by chemically isolating two different metals. Typical anti-seize paste OTOH acts as a donor of ions to both sides so any ion wanting to bond with another ion from the other side is now actually bonding to the voluntureering copper ions instead.
Not that I want to lecture anyone on this anyway.
Either, all input is welcomed.
EDIT: It seems Tomassini and I are thinking along the same lines which sounds rather comforting.