GREENVILLE, S.C. Cosign, a third-party guarantor platform designed to help qualified renters get approved while protecting property owners, has officially launched in Greenville, addressing a persistent gap between renter demand and the outdated qualification standards blocking access.According to data from CoStar, Greenville's rental market has grown significantly in recent years, with the region undergoing a nearly two-thirds apartment inventory expansion since 2010. Vacanc