I cut a set of stretchers on the CNC since its bed was large enough to accommodate their length.   It's much less harrowing than flush trimming narrow parts on the router table.

Each stretcher end has a 3/4" extension that will become the integral tenon.  The top two are the seat stretchers.  The bottom is the yoke that connects the arm pieces behind the seat back.

I didn't fully think through the process for clamping the pre-cut stretchers to the Pantorouter.  It turned out I had made things more difficult by doing that.   With the curved edges, I could no longer index the fence to keep the stretcher in the correct position.  I mulled over a couple options, and ended-up making an MDF filler piece to fill the gap and provide a straight edge.   The two seat stretchers have the same radius on top, so I could use the same filler piece for both.  I used some double-sided tape to hold it in place while cutting the tenon.

I'll need to do something similar for the yoke-shaped arm stretcher.   The curved filler idea works, but it's more fiddly than I like.   I'll change my process when I make the stretchers for the back in order to avoid using the filler.

With the two seat stretchers dry fit, I could start getting a preview of seat frame.