Hand sewn eyelets sound fragile.  Will they really withstand strong lacing? Yes, absolutely!  In my experience they are actually stronger and less likely to pull out than metal eyelets.  I’ve never had a hand-sewn eyelet tear out, but I’ve had many metal eyelets tear out.

One way to finish the stomacher would be to sew and assemble the stomacher just like the stays, and then add a floating lining at the end.  You can absolutely do that, and it’s the best method if you are hand-sewing your boning channels.  However, I prefer a different method.  

Here are some techniques to make marking and sewing the boning channels in the Scroop Patterns Cassandra Stays easier!