As for other thoughts on how to do this:
You can create the sectioned part(s) and place those and your main assembly
in a wrapper assembly, then use animate fade and disolve the whole
component(s) to reveal the interior components. Then, if there are moving
parts, animate those.
As far as calling it a limitation, I would say, it simply hasn't had a high
enough priority. There finite resources available and all have to vie for
those resources. As one email advised, one way to get attention to a feature
is to nominate it on in the AUGI forum and get it debated and voted on as a
requirement.
-Bill Bogan
Autodesk, MFG, Technical Publications