In this article, following up on our previous investigations on guided resonances (GRs) in photonic quasicrystal slabs based on octagonal (quasiperiodic) tilings, we present the salient results from a parametric study of the GR properties, varying the air/dielectric fraction, and the slab refractive index and thickness. Our results, obtained via full-wave simulations, show similar qualitative trends as those observed in the literature for periodic photonic crystal slabs