Hmm... Or perhaps you could package and upload a simple game project for testing purposes only, with the plugins I mentioned installed? That way, I can take a direct look on my side and help identify what the issue might be.
As for the Electron.js part, it is normal for the game to crash immediately on the very first launch.
That’s because I designed it so that, during the first run, it will automatically modify part of the RPG Maker MZ core code into a version that Electron.js can read, and it will also generate a file named replace_done.flag as a marker indicating that the modification has been completed.
After that, launching the game again should work normally.
However, if you’re seeing the infinite spinning loading circle again, my guess is that you may have restored the js folder back to its original version—the one that has not gone through the automatic modification process.
In that case, you can simply delete the replace_done.flag file, and the code replacement process will run again, converting the files into a version compatible with Electron.js.
By the way, I wanted to ask—did you upload your build to Steamworks through the web interface, or did you use the SteamPipeGUI tool?