Just for a start
Goodness the sad part is there is probably 20 wooden weapon topics.
Some cultures didn't train with wooden weapons and why would they? Unless wood somehow gains the weight and feel of steel I don't see why they would. Prevent Injuries? Pansy talk! it builds character!
Katana were much lighter and much more expencive but even then they did train with them occasionally.
-Also lets ignore that the Japanese fought with Wooden Katana without armor with the sole intention that bones would be broken. In fact death by wooden sword wasn't all that uncommon, you would be considered foolish if you thought you were safe because you were fighting with a wooden weapon.
Once again the real solution to training accidents isn't to take them out or make them supremely unlikely (As almost everyone was bound to have a few in their lifetime) but to stop Dwarves from wetting themselves and holing themselves up in their rooms for months because they stubbed their toe. Heck even then, while someone with a broken leg can't do all the kinds of training as their kin can, they still could do other forms of training.
Why arn't there more suggestions about that?
Note: I don't mind the suggestion that allows modded in wooden weapons. Mods usually are exempt from this
Note 2: The new armor revisions should also make armor more effective. Your not likely to have peirced hearts while sparing... Though I've only have three accidental deaths max in my forts (Yay I am amazing!)