Is it possible to have an app menu depth greater than 3?

Splunk will not display anything in an App menu with a depth greater than 3. In the below example, it shows as far as the menu "testing layer 3", which looks like it should be expandable (has a little arrow), but does not. Same goes if the views are moved forward one level to what would be level 5.

App's nav default.xml example (the xml will probably get formatted out of existence, although currently looks ok in the preview...its a structure with 4 menu layers before the views start):

<nav>
  <view name="ig_pci_overview" default="true"/>
    <collection label="testing layer 1">
      <collection label="testing layer 2">
        <collection label="testing layer 3">
          <collection label="testing layer 4">
            <view source="all" match="RST"/>
          </collection>
        </collection>
      </collection>
    </collection>
  <view name="flashtimeline" default='true' />
</nav>

I've wanted deeper menus on many occasions, so finally got around to asking on here if it is possible to get Splunk to show them. Anyone have any ideas?