Thank you for the info!
> 1. I noticed that the FileWebView2 plugin's folders expressions do not work in preview (I didn't test any of the other functions). Is this a bug or something that will not be possible with this WebView2 file system plugin?
Construct's normal preview runs in a browser, not WebView2, so WebView2 features are not available there. You can however check 'Export for Remote Preview' when exporting WebView2 to more conveniently test WebView2 features via Remote Preview.
Yeah, that is what I figured. But I saw in your opened ticket, that the File System api was worked around to skip the user verification, which is still in the beta branch. Once that will get in the stable branch, will the File System api be able to show this data in preview, or will we still need another plugin just for the webView2 features?
> If not, what is the suggested work method for supporting all operation systems in the same project?
If you still need macOS and Linux support, for simplicity I would advise to keep using NW.js for the time being. If you only need Windows support (and note that about 97% of Steam users use Windows) then I would recommend using WebView2 instead.
That might have been the case a few years ago, but the Steam Deck is running Linux and it grows in popularity every day. I can do without macOS, but Linux is a must these days.
> 3. Will it ever be possible to set a WebView2 app window to maximize in runtime?
It's already possible via a custom wrapper extension, but support is not yet built-in. You can however request fullscreen on startup with WebView2 just like you can with NW.js.
Yeah, I'm already using the fullscreen request, for when the player chooses Fullscreen mode, but if they switch to Window mode, I would still want the window to be maximized. Both when switching between the two and when running again in Window mode.