In all seriousness, using the PSP script, though it sounds easy, really probably isn't.
I'll admit, I haven't specifically looked at the FFT tools being used, but off the top of my head, what you'd have to do is insert the script.
For just the plot alone, you'd have to carefully catch every added scene and delete it, then, assuming the PSP script is in insertable form and formatted for the PSX version, you'd copy-paste it into every scene. Which is a lot of effort, although doable. I wouldn't blame Laggy for not doing it, to say the least, however. And it assumes a lot which may simply not be true.
Making LFT compatible with another patch, however, or making it so that anything in-battle would match the same translation, is a mountain of effort. LFT would require a separate patch entirely, one that rewrites every single new skill and either somehow excludes them from being patched, or, more likely, just patches the whole thing it's self. The net result is essentially redoing a substantial chunk of such a patch. If you ran such a patch, it would just overwrite all the in-game altered documentation for skills, which of course would lead to such things as a lot of new skills being named Bio or the game telling you that Reinforce was a Shell/Protect spell, etc.
Essentially, what sounds simple there is actually a week's casual effort or so, assuming everything went perfectly, which it probably would not. Kinda the irony of romhacking is how often that happens.