At least in my local version ...

The align dialog contents changes when you select the Node tool, and lets you align/distribute the selected nodes.

Align nodes dialog in action

For the momment, nodes are always aligned on the first selected node, but the select master combo box should be operational soon.

I am also looking for a way to show to the user which object/node is the current master. Maybe the Node could be drawn in red or any other color, but for objects I'm not sure this idea is very clever ...

Edit : Now distribute nodes also works :