Still in question given they are passing off that resin thing as official. It certainly doesn't look resin the movies-- but yeah, it could be pure CG... That said I feel like the would have had something for reference in the scene-- the way the blade lights up Luke's face I feel like there was some sort of practical saber there.You mentioned TLJ... Do we know if they made/used an FX version of Luke's green saber at all for TLJ? All I am aware of that we saw was the TFA table shot and the TLJ resin Hero. I'm thinking that they never even made a Luke FX for the ST.
I probably should have just stuck with the Darksaber reference.