I see the ML’s only have one set of binding posts. I know multi-channel receivers sometimes provide a menu option to assign spare channels so they may be used in a bi or tri-wire setup. I guess I don’t see how you would do this, unless of course bridging is specifically addressed in the manual. If so, the other posters are spot on.
Or, as Emily Litella would say- “never mind.”
Or, as Emily Litella would say- “never mind.”