The Sepulcher of Is-Artais (Pronounced: Ice-Are-Taze) is also done (though I have no plans to publish it). Why? It is, I feel, too specific to my personal campaign and not easily dropped into another setting. We're talking about a tardis-like ship here containing the Machine of Lum the Mad, Chemosit-like horrors fashioned after Mike Harrison's Viriconium stuff, Xag-Yas and more...If Zjelwyin Fall had been better received perhaps, but alas, the Sepulcher is of similar vein and therefore, I think, it will remain in outline form: sufficient for me to run, but not worth the trouble of polishing to completion.
Has your feeling about publishing The Sepulcher of Is-Artais changed?
At the time of your post (January 2020)---many months before the publication of Dream House of the Nether Prince---you were thinking that you might not publish either. I am hoping that DHotNP has sold better than ZF (?), and that its improved reception may have, perhaps, given you sufficient cause to consider completing The Sepulcher of Is-Artais, as your next publishing project?