Ohhh, so it's 8 lights, and the limitation is in Preview mode. Good to know.
Sorry I wasn't clear about this - yes, whenever I say "OpenGL", it means the hardware-accelerated Poser previews - not renders. The 8 lights limits is imposed by OpenGL, so it's not Poser's fault. DS also uses OpenGL for its previews, but it's not hardware-accelerated, and therefore cannot display more complex materials like Poser can, like shadows or the effects of bump/normal maps in real-time. This has persisted in DS for the longest time, but DAZ has recently added a new hardware-accelerated real-time PBR preview mode called "Filament", which not only can preview more complex materials like Poser does, but it can preview partial PBR materials, with some limitations.