Although I’m not a huge proponent for turning the Final Order troopers into clones, it would be a simple way to explain how they were able to man all of those Star Destroyers, as well as not have Finn kill his own former brothers in arms during the final battle.
I know someone already made a test of throwing in some of Temuera Morrison’s clone lines and grunts during the battle, but there is also another place or two where you can insert some more clone references.
First of all, you could replace this off-screen line during the First Order meeting:
“We’ll need to increase recruitments, harvest the galaxy’s young.”
Since this bears little weight in the overall plot to the movie, since the fleet seems ready by the next day, it could be used as good line of exposition to explain how they’re able to have this fleet manned in less than 24 hours. So, maybe you could have a new line like this:
“We’ll need to man the fleet, utilize their clone army.”
Later on in the movie, when the Resistance arrives on Exegol, a masked Final Order technician says, “Captain, we have Resistance craft incoming.”
We could use Morrison’s lines from the original Battlefront to construct a similar line, something simple like this:
“Sir, enemies sighted.”
Of course, we could just assume the red suits are new gear for First Order troopers, but since the Sith cult already has cloning technology, it could be an interesting tie-in.