Support for nesting wait directives?

[sstorie]

Do you know off hand if it's possible to nest wait directives inside each other? Something like

<wait until-not-null="relativelyQuickProperty">
  <wait-loading>...</wait-loading>
  <wait-done>
    ...a bunch of content...
    <wait until-not-null="someDelayedValue">
      ...
    </wait>
  </wait-done>
</wait>

I'm hoping to use this to show a status page, but one where the critical values load and show relatively quickly, and some supporting graphs are shown once their data is fetched (which takes longer).

Some initial testing shows that the inner wait seems to cause them all to wait, but I'm a little over me head on how these nested directives would interact.