If you keep getting the same guy making the same mistake MOR them. Its not worth the hassle at the subsequent board of inquiry " Why didn't you challenge the lack of / incorrect readback." Even better, make use of this open reporting thingy!! That starts at my unit this month sometime. Shoud be a hoot!!!!
Mats Part 1 - (I can't remember where) states that a suggested maximum of 3 instructions per transmission to avoid causing confusion.
TIO