Increased melt temp and mold temps work best for hiding glass. Excessive shear tends to break the glass fibers and can lower impact. Moderate screw rpm that finishes about 3-5 seconds before mold open is better. Do you know what the screw motor psi is? Over 1,500 means cold melt, less than around 900 could show high melt or long residence times. Is the resin FR or UV stable? These additives can make a reverse temp profile work better without making the additive bloom or yellowing the parts, or shear burning the resin. Rick.