When you say it cross references to ASTM A572 Gr 50, what are you using as your source? If you are using the UNS as your reference, it only compares chemistry, not the mechanical properties.
If the CMTR lists both the S355 and A572 Gr 50, I'm with Lawrence's position. Likewise, if the CMTR lists both S275jr and A1011. If both are listed, no problem. If not, I would hold judgement until I see what you are using as your source indicating they are equivalent.
Just saying - Al