Those thin little wires woven through the burlap provide a lot of additional support belive it or not and help keep the springs from digging into the foam.
Watch the videos on legendary's website, they omit them.
I put them back.. My rear seat bottom ones were still solid so I re-used them. Marked out 1 inch squares on the back of the new burlap and wove them back in. The front seat tops/ backs were good so I did the same, only they have a larger rounded end and are sewn into a pocket created in the burlap. My wife bent a few needles but got it done nicely. The front seat bottoms were bad and I used some floral wire from hobby lobby that was close to the diameter of the original. Also the wire was wrapped on the ends around some rolled paper substance. I substituded fabric cording from hobby lobby.
Not sure if all that is really needed, but the factory did it for a reason..
In addition there is "Listing Wire" wrapped in paper that gets hog ringed to the springs after the burlap is installed to give the tie points for the listing sleeves that contain the stiff steel rod.