In case anyone wants/needs it, I have been working on a more helpful (for me) SubEthaEdit mode for i7x/inform extensions.
Inform7.mode.zip (21.9 KB) (updated)
Most of my development has been in an i7x file separate from the main inform file, and I found the features in that side of the IDE to be too lacking. The main IDE is fine for my .inform file, and in fact I like it.
I found an inform mode already available online, but it looked like it wasn’t optimized for i7x extensions (if so, then it has far more highlighting for i6 than I will ever be familiar with. I added a bunch of syntax highlighting and symbols so that it automatically indexes Volumes, Books, Parts, Chapters, Sections - Tables, Definitions, etc. Then I added a bunch of PNG images for the symbol index.
I’ll be improving it as it frustrates me 
Or if others have suggestions I might add in more regex’s to highlight syntax.
If anyone could contribute
- an applescript for updating volume/book/chapter/part/section numbers it would be appreciated… my applescript is sorely lacking. SubEthaEdit is scriptable, but that’s not my forte.
- a working way to highlight multi-line comments without quotes or other highlightable terms in the comment getting highlighted. This is a frustrating “bug” in my mode, but the alternatives got messy quickly and while I’m pretty good at Regex, my understanding breaks at multiline processing with callbacks…nor could I figure out how to turn off syntax highlighting inside the comment anyway.
Edit: Updated the images in the file, more visible colors, added To decide to regex, and made sure all images show up correctly & backgrounds are properly transparent.