Had a thought for a slight change to TLJ. When Luke is “thinking” fleetingly about ending Ben Solo’s life, we should use Audio of Snoke saying something like “kill him!” If Snoke was the impetus for Luke’s actions, that would be much better than Luke himself thinking of doing it.
That would undermine it being Luke’s failure, though. xP
“Oh it was just Snoke!” is a cop-out to Luke having actually fucked up, and then just makes him look a little dumb for holding himself 100% accountable for something that wasn’t even really his fault.