Fixing macOS Big Sur Finder SIDEBAR width prefs from command line?

Question

My default sidebar width in Big Sur is too small. While I can click/drag to make folders look wider, that fix only works for folders that I open. If any application calls a new window to open - say for picking a file to attach or upload - the default windows that open render differently and my sidebar shortcuts once again can't be fully seen.

When I drill down into those prefs via CLI to change them, there seem to be about a dozen places in the finder's preferences file that mention the sidebar width:

defaults read com.apple.finder | grep SidebarWidth
        SidebarWidth = 174;
        SidebarWidth = 221;
        SidebarWidth = 221;
    "FK_SidebarWidth" = 294;
            SidebarWidthTenElevenOrLater = 217;
    NSNavSidebarWidth = 120;
        SidebarWidth = 178;
    SidebarWidth = 260;
        SidebarWidth = 135;
                SidebarWidth = 248;
            SidebarWidth = 0;
        SidebarWidth = 221;

I'll spare sharing the entire Finder preferences file as it's ginormous, sooo: I have questions!

1. Am I working with the right preference file?
2. Which of these mentions is the right one?

Thanks, all.

For @pion, here's the full code pull you'd requested:

WindowState =     (
        BROw,
                {
            EntryPoint = "file://localhost/Volumes/Mac%20OS%20X%20Install%20DVD/";
            ScrollPosition =             {
                h = 0;
                v = 0;
            };
            ShowToolbar = 0;
            SidebarWidth = 0;
            Target = "file://localhost/Volumes/Mac%20OS%20X%20Install%20DVD/";
            ViewHeight = 420;
            ViewStyle = icnv;
            WindowBounds =             {
                bottom = 590;
                left = 597;
                right = 1122;
                top = 170;
            };
        }
    );

Answer 1

Try

defaults delete com.apple.finder WindowState && killall Finder

Update:

Also try

defaults delete com.apple.finder NSNavSidebarWidth && killall Finder