Hi! One of the developers here. If anyone has any questions, comments, or feedback - we're all ears.
The primary focus of this project is to fill a niche that we feel is underserved by the larger projects like discourse. Thredded is built to be a compliment to an existing rails app, and not another entity that requires extra servers or management.
This codebase has been maintained in one way or another for over 15 years (through several different incarnations) so it's certainly not going anywhere. We're in it purely for the love of the development and the project. Let us know what you think :)