Serializing fiction on Substack - new tips for 2025?

I know this has been discussed before, but I’d like to hear what’s working or not working for others these days, now that it’s been some time since Thomas first did an episode on Substack. I recall that he did NOT recommend using Substack for fiction at the time, but I’ve noticed several writers here who have given it a go.

I did so myself a couple years ago, without much success, but am now thinking of relaunching my Substack serial and possibly using it as a perma-free (or maybe temp-free?) strategy leading up to the release of my book and audiobook on Amazon. In addition to that, the audiobook is partially recorded so far, and I could release that in a podcast format (either on Substack and/or other podcast platforms) prior to actual publication as well.

Any input on how to (re)launch fiction on Substack, with the aim of growing an audience - and possibly having an eventual source to pull launch team members from - would be appreciated.