The average performance is equivalent to Gross performance values, and the figures we use in operations are Net. Net is Gross reduced by a certain factor depending on the number of engines, and is not always applied, but generally it factors in the small variations in operating technique, errors in wind information etc. In particular, the 35 foot screen height is Net, thus the real altitude you would expect to see will be higher than that.
Using the figures as presented by the manufacturer will not put you on the limit. The average line pilot should always be able to fly to these numbers or, usually, better.