I would probably not sash it, but add borders instead or if you do sash it, maybe sash not each block but every 4 (4 block square) so you keep the diamond pattern of 4 blocks together
Heres my string quilt..
I used a foundation muslin leaving the center diagonals blank to get the lattice effect.I'm very happy with how it turned out. Yours will be gorgeous no matter what you do ;-)