Unless one of us sets out to actually experiment and come up with measurable results it is all guesswork .
There was recently a thread that speculated about the weight added by the glue we use to fix the rubbers to the blades. This is of course a bit different but it is quite amazing how weight can accumulate. At that occasion I measured the weight of an XVT gluesheet and came to 2.5 g or 5g for both sides.
Yeah. The thing with rubber or latex glue that is different is that the idea is for it to occupy space between the rubber and the blade and the latex or rubber substance in the glue is substantial. But it is true that we would have to take the glue that would have been put onto the blade, dry it and weigh it.
But it also has to be remembered that, when comparing the weight of two blades, where the glue to laminate the wood is the difference between weights, you are not comparing one blade with NO GLUE to another with a lot of glue. You would have to be comparing the weight of a blade that has enough glue to bond the wood, to a blade that has soooooo much glue that it would cause a material weight change in the blade.
That much glue may also cause the blade to end up thicker because 10 grams more glue on one blade than the amount of glue on a blade sufficiently glued would likely be quite a bit of glue. And when laminating wood plies, I don't think you put three or more layers of glue on the wood plies, for laminating. But you do, precisely do that when gluing rubbers to a blade, and it would make sense that a glue SHEET would not just be the equivalent of 1 thin layer of glue.
So, if you had two blades of the same make, lets say, two Viscarias, and one had enough more glue for the glue in the blade to cause it to weight 10 grams more than the other Viscaria and nothing else was different: if that kind of thing happened, a good company's quality control should catch the monumental difference in amounts of glue. Also, as the plies were being bound together in the press for laminating the wood, a lot of that excess glue would come out the sides and not stay between the wood plies.
I guess we should ask a blade maker for thoughts on how much of a difference in weight gluing anomalies could cause in two blades with the weight of everything else the same. But to me, a slip up of too much glue on one blade would be something that would likely be caught in various stages of the process of making the blades if the blade is from a decent company.