A couple of thoughts having had time to think about this.
First of all it isn't are replacement for twitter because even if you aren't part of twitter you can view posts and threads.
But as far as I know Spinster posts can only be seen by others who have signed up.
So although I think anyone who wastes their time of tweeter just shouldn't bother its as pointless as going to some strip club and trying to get the punters to think and behave reasonably, there is at least the benefit that those with gender critical views can be read by others. (The main value of twitter is the vain hope that mainstream media will pick up on some "twitter war" and amplify it, but this works against women as the media rarely reports pro women, let alone gender critical, tweets.)
this ability to publicly view posts is also one of the values of mumsnet talk (especialy FWR) as non members can read posts that represent gender critical views.
So it might be worth thinking what is the value of Spinster which doesn't have this public looking in aspect. Does it make it easier to plot and plan, or what .... ?
Please let me know if I am wrong about posts on Spinster not being viewable to non members.
But if I am right how should be make the most of this aspect?