Got about 30 MDF panels that have a fairly complicated field profile that I don’t want filled up with a thick primer.  Would like to shoot them with a thin sanding sealer to fill the typical cut MDF surface, so they can be sanded smooth and shot with SW Acrylic Latex.  The rails and stiles will be Poplar or soft Maple, and will be painted also.  The doors will be assembled before finishing.  They will go in a bathroom.  I was thinking about using nitro sanding sealer or shellac.  The fillers in these seem to be finer than typical WB sealers.  Suggestions? Thanks.