Apparently this is what you get when you disconnect animation speeds from the overall frame rate. He left it in as a keyboard shortcut in the newest version of his fix. It turns out Symphonia's animation is skeletal after all, which according to him means animations could be chopped into smaller segments of time, e.g. higher frame rates. He is likely about to drop it again, though.
He recently finished a complete texture upscale project and has been improving the fix's ability to decompress .7z files on the fly, so much so much that he could fit 30~ GB of textures into just over 5 (https://github.com/Kaldaien/TSF/releases/tag/tsfix_090).