She's been working to do that, actually. Originally, most (if not all) of LT's content was hardcoded in the Java files, but she's been creating XML loaders for that stuff. Map data, encounter data, status effects, dialogue trees, and even special sex scenes are defined with external files. The major problem is that this sort of thing should really be done in the original drafting and design phase, not deep into the game's development.
Additionally, that also doesn't take into account the fact that the engine, as if currently stands, doesn't scale well. Some of that is being alleviated in the next version by AceXP's unfound children patch, and I'm prototyping a fix for another performance issue, but there are still a laundry list of other problems that need addressed, otherwise the game will continue to get slower and slower as the story is expanded.
Really, it's all too much for one person. Inno really needs to find a trusted partner who understands Java at a low level in order to fix the engine or, as I suggested before, introduce a bug bounty system. The game's source may be available for perusal and modification, but that only gets you so far.