Heres a test VFX shot of Rey shooting out Force Lightning instead of the Force Push to signify her instability, the compression makes it look slightly weird but it’s okay: https://streamable.com/cqtffo
It looks great! Absolutely believable that it’s from the theatrical cut.
While I agree with Hal that less is more with the lightning, I wonder if a tiny tendril could reach Finn? More like it’s conducted to him than it’s what’s throwing him backwards. Currently the lightning completely vanishes on the cut, and since it’s cutting on action, I think there needs to be even a minuscule amount of lightning in the second shot for continuity of movement.