Maya :: Convert Displace To Polygons With History?

There seem to be some errors in the code for Modify > Convert > Displacement to Polygons with History. My scene uses an animated displacement map, coming from an image sequence. The displacement works as advertised, but I keep getting execution errors. Here is the code for the offending expression, which was created silently when I issued the conversion command:

if(!Disc1_MeshShapeDisplacement1.disableDisplacementUpdates){
updateAnimatedDisplacement( "Disc1_MeshShape","Disc1_MeshShapeDisplacement1","displacementShader1.displacement");
}
//Setting the following attribute here dirties the mesh so Mental Ray updates properly
Disc1_MeshShapeDisplacement1.featureDisplacement = 0;
//The next two lines cause the expression to trigger when editing attributes that affect the displacement
float $dummy = displacementShader1.displacement;
Disc1_MeshDisplacement1.inheritsTransform = true;

The only way I can stop the constant error messages is to comment out the code or disable expression evaluation.

The error messages are annoying, but I can live with that. The real problem comes when I try to select keyframes in the timeline. I shift-drag across keys to select them, and they highlight at first, but then the highlighting immediately goes away. I am forced to use the Dope Sheet instead. Disabling expressions doesn't work, so I don't know if this problem is related to the displacement expression or not.

Displacement in Maya has a very bad reputation, and based on my experience, it's well-deserved. Another issue I have is that after conversion with history, multiple shape and transform nodes are visible in the Outliner, and it is not clear what's going on. The documentation for this feature is only two lines long, and does not explain anything. Apparently there is a pre-displacement shape and a post-displacement shape in the scene, sort of like how nCloth has an input and output mesh. But with displacement w/ history, users get no guidance on how all of this is supposed to work.