Surely if you just drop the yokes down the forks you are lowering the top yoke no???
Not dropping the forks through the yokes, but actually lowering the yoke towards the headstock, the stock lock nut must be 10-12mm thick, I've looked and the thread on the stem (for the nut on the top of the yoke) would need extending and the stem could be shortened.
Going to ask the engineer, who will hopefully swapping stems, how much hassle (cost) it would be to machine the lock nut, extend the thread and shorten the stem to suit.
May sound a lot of grief for a few mm but if going to all the hassle of swapping front ends then why not