On October 12th, Conquest! launched on the Steam platform. Like other hosting sites, Steam has its share of idiosyncrasies but once those were worked out I was able to launch successfully. The guide that helped me the most was here: The Simple Guide to Steamworks API in Unity: Uploading Builds | by George Dutton | Finite Guild | Medium
Note that when the Steam platform first created the project for Conquest! it failed to create the default packages. After spending a day attempting to debug this myself (thinking it was a problem with the build or configuration) I opened a support ticket and learned this sometimes happen. Support created the default packages and everything starting working.
Adding Conquest! on Steam has seen the biggest increase in the player base ever (including when it was originally on IRC). Conquest! is still difficult to learn and the UI has some usability "quirks" so the overall retention rate is small but I would strongly recommend getting any game listed there.
I also went back and updated my submissions to Itch.io and Game Jolt. I'm not sure how much of an impact these platforms have but every little bit helps. I tried to submit to Gog.com but in their automated email back to me, they indicated an automatic pass on free games. So I'll keep looking for other platforms to list Conquest! on.
James has been working on Conquest! since 1993.