I posted a test of black robe Rey earlier in the thread, which might be the one you’re thinking of. I used EBSynth but it still required a lot of manual masking because the tracking wasn’t great. You can see around her shoulders where I had to mask the original footage back in because EBSynth kept wanting to spread the black to the background as the shot pans (probably would’ve made more sense to start with the ending frame and process it backwards…).
I did try a test of one shot of the end scene using Rotobrush 2.0 instead, but I couldn’t get that to track any better, so it still required me to do a bunch of almost frame-by-frame masking - ultimately I decided it added basically nothing to the film for the time investment and stopped working on it.
I didn’t realise how much I needed this until I saw it. This is such a staggeringly huge improvement, and an almost obscenely impressive piece of VFX work. Well done.