If you want to build a fanbase and get beta testing for your WIP, as far as I know, this forum the best place to do it by a zillion miles.
The next best place I can think of is intfiction, but it has much less users by the looks of it, and not everyone there is interested in choice-based IF, let alone choicescript. (I got New User of the Month there with literally three posts and zero topics created).
The Hosted Games subreddit is another option, but I don’t know how viable it is to build a WIP thread there. Has anyone tried it?
I don’t know if there are other good places to build an audience. If anyone knows, I’d definitely like to hear more. Please and Thank you.
As writers, we need positive feedback to keep us going, or even something as simple as a like or “good luck”. 
Maybe there’s an army of lurkers out there who enjoy our work, but we need to see the positive feedback to feel this endeavor is worth our time.
I think this is the thread that was referenced. It was quite upsetting to read, and probably one of my worst fears as a writer. 