Yes, it appears that the shot is already reversed and inverted.
If anybody is still interested, I think a good first step in making the castle appear more abandoned is removing the glowing “windows” of lava on the front of the castle.I actually tried that at one point, but it made the castle look far less menacing.
Also, to my thinking, the lava would continue to flow regardless of the castle being abandoned. I can’t remember all of the other canon/non-canon stories about the castle, but I like to think of the beings that Kylo is fighting as cult members who likely are still inhabiting the castle as a dark shrine of sorts.
Just my thoughts.
Is it possible for you to get a 4k version of that scene so the crop doesn’t lose detail?
If Hal isn’t happy with us talking about this here I’ll gladly brainstorm on my Last Hope thread. I don’t know how to link to it.