I want to put out Women's Wrongs as a serialised novel, how's Buttondown treating you as a platform?
Buttondown is honestly pretty good. It's a small operation, so there are some minor things I'd love added (some kind of easy way for readers to convert the mails to pdf or epub) that probably won't happen even though the guy behind it IS very receptive to feedback and appears to be pretty nice. I remember reaching out to the webmaster about something I didn't quite love about the process of publishing an e-mail (I can't quite recall the details, but there was an extra step after you clicked "send" that wasn't intuitive to me) that was fixed in the next major update, so that certainly set a pleasant tone to proceedings.
On the practical side of things, composing and formatting my chapter emails is pretty simple, and scheduling is similarly painless. Hell, you can edit the mails if you miss anything major, although that's for the persistent archives moreso than your direct subscribers. That's how Email works, though, so no hate there, it's good for developing a "measure twice cut once" mindset.
As for concerns, my only real worry as a Buttondown user is that an upper limit of 100 subscribers for free accounts such as the one I use. I have decided I'll try some sort of crowdfunding if it ever gets there (as the paid tiers of Buttondown also allows one to have premium subscription tiers that you can send exclusive content such as short stories or character bios to) but I'm always wary of monetization. Either way, my subscriber count has not gotten close enough for this to be a concern yet, but I do stay on that grind, and am generally of an anxious disposition.
Overall, I think Buttondown is a pretty solid service, and a good alternative for free selfpub currently. Can't speak to how the monetization features and that work, but if the main priority is to put a book where someone might read it, it is a damn good alternative.