Browser Instrument Layout

Is it possible to modify (move/add/delete instruments) the contents or organization of the instrument list in the browser? I've created a custom plugin layout and would like to do the same for instruments but haven't found a way to do so.
 
I have created a custom synth folder which I can use in the FX bin just fine except that subfolders under the three main folders (DXi, VSTi, and VST3i) don't open. So the subfolders are visible but not the synths in the folders. When I click on Synth button in the browser, the Instruments all disappear and the Instrument heading under the Synth button is replaced with None. It appears that the only way to get the instruments back is to close Sonar and reopen it. There also isn't a Manage Layouts dropdown for synths in the Browser similar to the one for Plugins.
 
At this point this looks like a bug, or a feature that the developers haven't gotten to yet. So, I'm going report it as a bug.
 
Let me know if I'm missing something, which is pretty common for me.
 
Bill