How should an ACFT failure be appropriately reflected on an NCOER? Will the NCO be subject to QMP?

MSG (Join to see), the book answers you know:
"The rater will address a “FAIL” entry for APFT within the comment section provided. Bullet comments for “FAIL” entries may include the reasons for failure or note any progress toward meeting physical fitness standards of AR 350 – 1."

However, to your question, my teams have always interpreted that a failed ACFT will impact "d. Presence" because of the attribution to it in DA PAM 623-3: "NCOs who meet Army minimum standards for APFT but fail to meet unit standards will not be given rating of “DID NOT MEET
STANDARDS” within block d “PRESENCE” for physical fitness if such rating is based solely on the failure to meet unit APFT standards."

This idea is reinforced in ADP 6-22 ARMY LEADERSHIP AND THE PROFESSION:
"Leaders promote policies and practices to maintain total fitness for themselves and their subordinates." and "It is a leader’s duty to stay healthy and fit since the leader’s decisions affect the welfare of the entire organization." (p. 3-2)

That said, simply failing the ACFT may not be grounds for DNMS "d. Presence", but it should be considered heavily alongside Military and professional bearing, Confidence, and Resilience and at the very least a conversation of its impact on the rater's perception of the rating for this category.

I may be retired for a minute or so, but a failure has always been -- "Did Not Meet Standard". As for QMP, it is a known potential consequence for not meeting the standard.

Negative