Pasquenal: That " using a standard sieve " is a big " IF". Not wanting to argue with you, but I recall reading a post from someone, who had compared the powders and found the Swiss 3Fg powder to be much faster burning than the Goex. And, apparently ,in the powder industry, there are a range of diameters that can overlap some what, from one " size " to the next. That is the reason that some shooters who are serious about target shooting have bought their own sieves, and screen the powders they buy themselves before using them in their guns. Their chronographs tell them that this caution is paying off with small deviations in velocity from shot to shot.
Having said all this, If someone is just using this powder to shoot off-hand, plink, or even hunt large game such as deer, I think the advice to reduce the load 10 % and then test fire it for group and POI is all that would be needed. Not everyone- probably the vast majority of NL shooters- is interested in fine accuracy that a target shooter demands.
