Oh, I get it ...
There are actually four types of Campag 11 speed lockring. And of this, you will note that none of them actually come with the part no. marked on them.
And just to confuse people like me even further ... In the Tech Doc that comes with cassettes, the z11 lockring is drawn with the thin washer thingy, but the z12 lockring is drawn without.
You are trying to over-think this.
There are two lockrings in alloy, two for the new 11s unranged cassette, in steel, for 11s.
Campagnolo occasionally introduce a running change where they don't necessarily prepare new drawings for it in the tech docs - the tech docs are mostly targetted at competent, trained mechanics and the training that is now offered includes detailed points around those running changes.
If the lockring is 11s for 11T top sprocket (marked Z-11) and it has an integral shim washer (you have to try to remove it, it won't fall off spontaneously unless damaged) Use this lockring, as supplied, for 11s with 11T top.
If the lockring is 11s for 12T (or 13T) top sprocket, no differentiator marked - again, use it for what it was intended for, without modification.
The new steel 11T lockrings are designed specifically for use with the new Cassette with alloy spacers and so have a longer threaded portion and are marked with the increased torque setting of 50 nm, specific to the new cassettes. Again they are marked either z-11, or have no marking for top sprocket size. Again, use unmodified, as indicated.
Where there are occasionally problems (and it's one of the many reasons that it's contractually forbidden for OEM to sell into the aftermarket) is if an OEM sends a bunch of cassettes out with the wrong lockrings, as they are seperately packaged in some cases. This is unlikely to apply with Chorus and upwards because pacakging is normally in individual boxes, even at OEM.