I would like to coat my pieces with a product that leaves a more
natural or semi-matte surface. Any recommendations for this
purpose and result?
Try leaving your surface as you would like it to appear before you
patinate it. I frequently use LOS on textured, unpolished
surfaces...it's not the LOS which is polishing the metal. Also, you
can leave the piece submerged in LOS for much longer than you
normally do, and a rough, broken surface will appear on sterling,
looking like peeling, rusted steel.