yeah inno made her own custom parser, all in all even if it ends slow (i don't think it does, it'd need a lot of parsable stuff) it's far from the biggest problemThings might have improved since the last time I looked at it (it's been well over a year since I've really done a deep dive on the source), but the way the JS engine was called before wasn't very efficient. If I remember correctly, it would set up and tear down the interpreter every time it ran an expression. That is, anything contained within square brackets in the XML, such as "[npc.Name] takes a closer look at [npc.herself]". Plus, "npc.Name" and "npc.herself" would both be evaluated by a heavy JS parser, which is quite heavy.
iirc there could still be many ways to make the base webEngine faster like async renders for parts of the screen but it clearly ain't there (and would prolly ask for a ton of UI bs)I was honestly kind of surprised at how old and clunky JavaFX's WebKit build seems to be. JxBrowser seems like it would be a good replacement in this case, perhaps with JFX controls for other parts of the UI.
JxBrowser also has its own JS engine. I wonder if that could be used independently of the rendering engine, and if it would outperform Nashorn. Might be worth looking into.
jxbrowser really seems like the one true way to fix it, in the worst case scenario it's 3x faster, and since it'll allow gpu acceleration and so much more i expect the wait time between anything to be much more affected. it's not like there's complex stuff, just a fuckton of stuff