Right, it shouldn’t spark IMO at the DSII duel.
Also, Rey’s saber lights are green and blue, referencing presumably Luke and Leia’s sabers but not that she used their crystals. Having green and purple would retain this nod for this edit. I’d prefer that over blue and purple.
I think a subtle flicker/distortion to signify wear and tear of this old saber would be best for DSII moment thats already been discussed; if not there maybe another place in the film once or twice, don’t think it should fully shut off or do a full on spark out. I like the idea of the Saber’s breaking after Palpatine confrontation though.