It seems to me that a lot of the time, we tend to get hung up in EXACT scale measurement down to the proverbial "gnat's eyelash". when in fact many measurements that are even being discussed in this thread are not readily discernible to the ordinary, unassisted human eye. In addition, when discussing wood (balsa, basswood, or even hardwoods) that's a material that is virtually impossible to cut micrometer perfect and have it stay that way, due to it's being a porous, moisture-sensitive material. For example, basswood cut to perfect shape at a factory someplace will NOT hold the same width or thickness in say, Phoenix AZ in July as it might have in other parts of the country with much more humid conditions (ever wonder why a cabinet door (or even wooden door that is part of one's dwelling) doesn't always fit the same at differences throughout the year?
Five or even ten thousandths of an inch in the thickness or width of a 1/25 or 1/24 scale basswood 2X4 stud frankly will not be seen by even the most discriminating viewer of a diorama building, as long as its in a wooden structure, not something laid onto a finely machined surface (and who among us does that either in metal or plastic to combine with wood?).
All that said, in the field of model railroading, there do exist 1/48 scale ("O Scale) sizes of scale lumber. Now, 1/48 scale is exactly half the size of 1/24 scale, so a scale 4X8 plank in 1/48 scale will be a 2X4 in 1/24 (true 2X4's are cut to 2" X 4", and then planed down to remove all the rough splintering before they are sold for building a house (originally as much for fire prevention as anything else), and if one is replicating a wooden frame building constructed say, prior to the late 1930's, unplanned structural lumber was pretty much what they used.
Another thing is the "Illusion of real" here: In scale modeling, we often put up with little compromises, for varied reasons, but if the end result looks realistic, minute variances in thickness and weight of material really do tend to disappear, because the whole presentation just seems to scream "REAL" and/or "ACCURATE".
Just some thoughts I have on the subject.