Thanks for the link. It does not answer the question directly. However, it does state that the turnbuckles are 3mm threads, and that the plastic ball link holes where drilled to accommodate these 3mm turnbuckles. This would be consistent with the link rods being 2.5mm.
Still, I would also like to know how deeply the 107-043 link rods can be threaded into the 107-100 plastic ball links. The manual states that these 43mm long 107-043 link rods are used for both the 3 cyclics and the 2 pitch links. This would mean that the pitch links with 28mm rod exposed (page 48) would have 7.5mm of thread into the plastic ball link, which is reasonable. However, for the cyclics with only 19.3mm exposed rod would mean 11.85mm of thread into the plastic ball link, which is quite a bit.