ExtJS ComponentQuery and Dynamic content

I have a layout with multiple grids, and they all use RowEditing plugin. I am trying to use Ext.ComponentQuery.query to get access to the embedded RowEditor buttons on specific grids, but am unable to figure out how to properly traverse things. I wonder if it has to do with the RowEditor and buttons being added dynamically - though I cannot find anything to confirm that is expected or not.

// #update is Never found Ext.ComponentQuery.query("#myGrid")[0].down("#update");

// Will find all the RowEditor update buttons on the page Ext.ComponentQuery.query("#update");

// I can find xtype roweditorbuttons, but up() doesn't point to anything (expected something about my target grid) Ext.ComponentQuery.query("roweditorbuttons")[0].up()

How can I get access to these button controls