Some experiments have been done with Duel of the Fates or Battle of the Heroes being part of the Kylo/Rey fight. Here’s different timing examples.

Battle of the Heroes:
https://www.youtube.com/watch?v=dOpRpYSXfkU
This one is well done–it also uses timing cues from the original lava fight, 1:12 is a good example.

This one uses the crescendos better for the force blocks:
https://www.youtube.com/watch?v=XjMVwE-d4yU

Duel of the Fates:
https://www.youtube.com/watch?v=djWxPM_41dQ
Good use of the low key at 1:35, but the timing of the Force-blocks doesn’t 100% match.

This one has slightly better timing of Duel’s chanting at the force block moments:
https://www.youtube.com/watch?v=PYFlmVw4WUg

Interesting split screen comparison between Anakin/Obi-Wan and Rey/Kylo:
https://www.youtube.com/watch?v=iCGpbotwRXw