First of all thanks for creating this custom control. I am using an Application Layout and have placed a panel in the MastFooter Facet and within that panel have placed the Debug Toolbar. However, the Debug Toolbar is still showing in the bannerUtilityLinks Facet rather than the MastFooter Facet. Looking at the code I am guess it is because of this style setting for the debugToolbar div:
<xp:this.style><![CDATA[#{javascript:"position: absolute; " +
(compositeData.collapseTo == "right" ? "right: 0;" : "left: 0;")}]]></xp:this.style>
and regardless of which position I use it doesn't display within the MastFooter Facet. The MastFooter Facet is an unnamed type.