Created attachment 131357 [details]
nps snapshot

The constructor of FindBugsPanel does this:
----
        defaultsToDisabled = cc != null;
        WORKER.post(new Runnable() {
            @Override public void run() {
                final TreeNode root = backgroundInit();
                
                SwingUtilities.invokeLater(new Runnable() {
                    @Override public void run() {
                        FindBugsPanel.this.removeAll();
                        FindBugsPanel.this.uiInit(filter, root, cc);
                    }
                });
            }
        });

        setLayout(new GridBagLayout());
        add(new JLabel(Bundle.LBL_Loading()), new GridBagConstraints());
----

I don't know how it could do less, or how I could make it work faster. In fact, the snapshot shows 1238ms spent in this constructor, out of which 1174 is spent in JPanel's constructor, ultimately spent in classloading, which spends the time in opening the zip files. So I guess its the classloading that needs to be made faster. (Remaining 63.5ms is spent in Bundle.LBL_Loading() - I can stop using NbBundle.Messages, if that is desired.)

The only way to deal with this is to preload the classes outside of EDT. Anyway it is 3s in 7.3beta, single report. Classifies at most to P4 and closing anyway while waiting for more reports.