Extract that data out as well and group it as following:
How confident are you that the steelwork has been modelled correctly in relation to cut backs and extensions. If these are not done correctly then the tonnage will be wrong, or you just allow for a reasonable allowance for “Revit Modelling”(eg the automatic extensions/cut backs).
Just something to always think about especially if you are sending this information to contractors/cost consultants as they may hold you to this tonnage.