This looks very interesting and promising! 

Love the design picture here! Did you use Figma?  

I looked at  the page and I think it'd be helpful if there was also a tutorial video. Or if you're going to run the tool let it be an empty one where there's tutorial features that can walk the player through how to start writing stuff vs just introducing them to a page where there's already stuff.  I think it'd be more immersive at least than having to pick and comb through a project that's already been started. I can see stuff and guess what it's for but a walkthrough would be nice.

Here's my thoughts on Twine and a few things I hate.

1.  How tedious it becomes to edit. 

Say for example I  don't like a character's name anymore and choose to change it, I can use the magnifying glass to find something in the passage and change it, but it's only for that single passage. This becomes incredibly tedious if you have multiple passages.  So if you're going to make something similar,  I'd say make sure users can edit things in bulk or an identifying feature  that allows characters/dialog sources/items etc to be defined, so little things like that can be easily fixed instead of having to comb through multiple plus passages. Also maybe add in an assistant proofreader?

2. Add different format template options. Learning about html and css has been fun at times, but other times I just want to be able to focus on my writing and not be distracted by formatting immediately. I'm a visual person so I'm the type who gets distracted if I can't fix. Having to burn through time looking up how to make those changes can be tedious depending on how readily available the information is out there- thankful google's ai has been most helpful to me in that regard but still. 

It's a huge time suck. Having a few premade templates, formats or features that allows you to  quickly edit font, text, borders, spacing etc, would be helpful, can edit in high detail later. 

Those are just my two tidbits you can take lightly. 

I heard you could make images with chat gpt but I had no idea it could learn to make images this good, that's surprising.