I have heard a lot of good things about this game though I am undecided on buying at some point. I also prefer to purchase fully finished or close-to-finished products. As an offline installer-only user, I check the "What did just update?" thread religiously. It seems to me that this game is very frequently updated though my original impression was that it was complete. Is there any sort of roadmap on when all the updates (or at least most of them) will be done?

Please don't get me wrong; I understand modern games have a different sort of model where there is a value of receiving additional updates after release and that is probably what is the case here. I appreciate the developer supporting their game. It's just annoying to have to redownload and redownload games when there are updates. If I know that a mostly-done version is coming by say, Jan 2021, then that's easier to wait and just get that if I wanted.

That's not quite the same question but I definitely understand your concern. For what its worth, a member of GOG staff recently expressed to me that the DRM-free offline installers are not going anywhere. That was very nice to hear and reassuring!

My understanding of why they are not updated simultaneously is because the client allows developers to "automate/push" updates on the "Scheme" platform (as I call it) as well as on the Galaxy client whereas the offline installers need some sort of "manual" work. I am sure someone more technical than me can explain it better and more accurately than that but basically I don't think what you are saying can be "solved". In other words, if there was no Galaxy, it seems like we would still be waiting a day or two for the offline installer compared to the Scheme version. I am fine with that general idea as long as we have DRM-free offline installers with no requirement :)

Here's hoping you make the shift to GOG. All games here can at least in singleplayer mode be played without Galaxy, you go to your game library in the browser, click on a game, and click "Download Offline Backup Installers", which will give you links (sometimes multiple files, especially for bigger games) that you can download through your browser and then you have the offline installer. Some multiplayer modes do require Galaxy (because they were originally designed for Scheme which incentivizes developers to be lazy and just have client-required multiplayer).

The gamepages in the store will tell you around/below the system requirements if a game requires Galaxy or some other type of client for multiplayer (a few of the strategy games want a third party account but usually have other, non-account required options like for local multiplayer with hotseat).