Issues
As someone who works with small press and self-publishing, a great thing about forges is having an issue or ticket tracking system. This is a place where a reader can report a mistake or typo with your story and you have a chance to fix it. A good example is Sand and Blood's.
Issue tracking isn't required to write, but I hate finding that people have been glossing over typos when I would rather fix them and then push up an update to the ebook vendors.
Using Issues for Writing
I also use issues to track things I need to do with the project. Sometimes, I'll realize I need to go through and fix someone's name or look for overuse for gerunds. I can write up an issue for myself (or put it in the TASKS.md file) and then keep on whatever I was doing.
Then, later once I finish whatever round I'm working on, I can look at the outstanding issues, pick one, and fix it. That way, I don't have to worry about remembering after the fact.
🛈 I recently started working on a tool that let's me doing them easily from the command line called Fiss but that is still in a very rough place and not quite ready for general usage.
Using Issues for Publishing
I also use issues heavily when I'm writing down all the tasks that need to be done to publish the book. Since most places allow for due dates on issues, I can figure out the day I hope to publish and then work backwards knowing it will take 3-5 weeks for Ingram to send me a copy but the editor needs two months before that before I can get the print copy. Putting all those pieces together in a single place helps with the overwhelming anxiety of publishing but also gives me a check list.