If we speak about Cross for Merit in War (OEK 2717), I have just read the paper of Neal O'Connor about this cross in his book. When Duke Bernhard of Saxe Meiningen created this cross on March 7, 1916 " it is to recognize sepcial merit on the part of officers in the war, both in action and behind the lines" p . 187 of Tome 5.
And the Medal for Merit in War (OEK Nr. 2718); this cross was created same date as above but"fro non commissioned officers and men".
For the moment I have never seen on photo and in text Cross for Merit in War awarded for NCO. I have a doubt if Felwebel Leutnant is consider as officer or NCO.
Christophe