What would you discuss in an SLC NCOPD on the actual role of a SNCO for military funeral honors?

Organize your troops and rehearsal is a must as many soldiers have never been on the detail. I'm sure some have - use them to assist after explaining what you want them to help with so they know what you expect. Most mess-ups occur because 'everyone's got this' - then they fumble.
There will be fumbles - don't sweat them as the rehearsal will iron them out - except when one of my soldiers ribbons popped off his (old army) dress green blouse and fell into the hole. NO one else noticed and the soldiers didn't drop the casket (or laugh, or panic) and the rest of the service went fine. We even had the diggers recover them after everyone left as the casket was only lowered and not covered over.
You're the supervisor so do the rehearsals until they're correct 3 times with your soldiers. Here are some key points I've found over the years which bite units again and again so they need to be practiced before departure from your unit because you do not have time once you arrive at the location.
Practice with a casket loaded (heavy as possible) with weights ,
Make your the Firing Squad shoot in sequence and that they understand the commands (retirees forget or civilians volunteers don't know things).
Make sure the bugler sounds "Taps" and it is sounded correctly (no fancy toots).
Never accept last minute 'replacements' because its screws everyone up who had made the rehearsals - they are a team now.

Here is what the Old Guard uses at Arlington Cemetery:
Sequence of Events for Military Funeral Honors
Burial at Arlington National Cemetery
1. The caisson or funeral coach arrives at gravesite, military members present arms (renders a salute).
2. Casket team secures the casket, non-commissioned officer-in-charge (NCOIC), officer-in-charge (OIC), and chaplain salute.
3. Chaplain leads the way to gravesite, followed by casket team.
4. Casket team sets down the casket and secures the flag.
5. The NCOIC/OIC ensures the flag is stretched out and level, and centered over the casket.
6. The family is seated.
7. NCOIC/OIC backs away and the chaplain, military or civilian, will perform the service.
8. At conclusion of interment service and before benediction, a cannon salute is fired for those eligible (i.e., general officers).
9. Chaplain concludes his service and backs away, NCOIC/OIC steps up to the casket.
10. The cemetery representative will ask all family members to rise for honors.
11. The NCOIC/OIC presents arms to initiate the rifle volley.
12. Rifle volley complete; bugler plays 'Taps.'
13. Family will be asked to be seated.
14. Casket team leader starts to fold the flag.
15. Flag fold complete, and the flag is passed to the NCOIC, OIC.
16. Casket team leaves gravesite.
17. The flag is presented to the next of kin.
18. For veterans of the Army, Air Force, Navy and Coast Guard, an Arlington Lady presents cards of condolence to the next of kin on behalf of their service chief and the lady herself.
19. Chaplain/family clergy extend condolences.
20.Cemetery representative announces that the service is concluded.
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I hope this helps. Good Luck.

When I was stationed at Fort Drum in 2000; the Honors teams were decentralized to the units so my SNCO just coordinated the logistics; while I as an E5 handled rehearsals on casket movement, rifles, flag folding and their PRT. I also conducted the uniform inspections and POC coordination with the funeral homes from Albany, NY all the way to Boston, MA with an O1 as my OIC to do the flag presentation to the recipient. Fast forward 13 years, I'm stationed at Fort Gordon. Here the installation manages Honors team with a GS civilian coordinating everything logistically. Our mission ranged from funeral honors to retirement ceremonies to parade details. My primary role in this organization was to manage the 7 teams, monitor/evaluate rehearsals, random uniform inspections, facility management and the occasional funeral ceremony/dignitary event if my other duties didn't interfere. We had no OIC for funerals. Either I was presenting the flag or one of my E6's who were on my teams. So as you can see from my experience, your role may vary depending on the installation your at.

As you can see from my profile photo, I'm a bugler and have been "doing" funerals and committals for 35 years. As a retiree living in a rural area, I have scheduled and organized funeral honors as the DOD Funeral Honors "System" isn't always "there" for veterans or retirees. I serve as a retiree on the USAF Honor Guard for Maine (named best USAF Honor Guard in the Northeast a couple of years ago) and I have sounded Taps, folded, fired and presented when necessary. NCOIC? One summer a couple of years ago, I did several funerals with a 20 year old female airman who was the NCOIC. Due to shortage of personnel, we could do a two person funeral detail. I would fold to her, march off to my pre-postioned bugle while she stood honors, sound Taps and she would present. I would steer the funeral directors and clergy to her on site and refer to her as "boss". It was The Army Honor Guard here in Maine is the responsibility of the National Guard as in many states. They do not use a live bugler unless one is requested by the family through Bugles Across America (a volunteer organization dedicated to providing live buglers rather than the "fake" bugle used by Honor Guards.) The USCG funerals are conducted by volunteers from nearby detachments. Their command requests buglers from BAA and I often have to provide some guidance on site although one of the two or three assigned would be NCOIC. Navy and Marines use the ceremonial bugle unless a family member requests a live bugler through BAA.
Often, we modify protocol given the circumstances but the bottom line is to provide a dignified remembrance for the family. Bottom line: Be military but be prepared to be flexible!

PS: You may have noticed that I am Army and as bugler, stand aside for the parent service representative to present unless there are special circumstances. This past year, twice, the honor guard did not show up for a WWII Marine and a Korean War soldier. With 45 minutes to spare and my 20 year old Air National Guard grandson in town, my cell phone got him to the grave site in Class A's and with me, provided respectable funeral honors. He is an Eagle Scout and has experience folding. I folded to him, he stood honors as I marched off to my pre-positioned bugle, sounded Taps as he presented just like a "pro". The family didn't know any different and I was a "wicked" proud grandfather.