Hi there. We also use Twine/Harlowe, for our longform Gamebooks (100k+ words).
What issues are you facing?
We’ve tried a number of options, but found Twine to be the “least worst”. We’ve found decent workarounds for getting the data out and usable for ebooks and InDesign, our preferred package for paperback/hardback layouts.
We’ve even got a fast spellcheck process sorted.
Hello all 
I’ve enjoyed several Interactive Fiction titles over the years. I haven’t played that many overall, but I hope to explore more soon.
I am creating a few things with Twine and Inform. With luck they’ll be ready to share before long.
I haven’t posted until today, but I’ve been grateful for the various pieces of info I have found here.
Cheers!
Daz.
Welcome @Dasra I hope you have a good and productive time here.
Hi. I’m the author of Decker, a multimedia sketchpad application.
Many of Decker’s users are interested in authoring visual novels, choose-your-own-adventure games, or in some cases even parser-based interactive fiction, and I’ve developed a number of libraries and extensions for Decker to support these use-cases. I joined this forum in the hope that I can answer questions any IF authors or fans may have about Decker and help raise awareness of the tools we have to offer the interactive fiction community.
Hell yeah, nice to see you joining the community @InternetJanitor ! Really appreciate your contributions to the scene though I haven’t played with Decker yet myself.