Wish I could help but I rarely get defs. It does look to me like it is drawing the stored energy from the fan leaves, and the budsites around the yellowing seem to be filling out. Veg nutes sound good in theory, but perhaps those will be colas/nugs that will be done earlier than the rest of the plant?
Only 17 Days till you have a 70 Day plant, not rare for autos to be finnishing up around then(not knowing the strain though)
Last 2 pics look quite filled out:thumbs: but that third isn't nearly done:karma Cloud:
EDIT: Just saw KOs message, good info there.