Maybe a little late…
I find that in Wavelab 7 in El Capitan on a quad core i7 iMac, I get a blank white space, regardless of the plugin. The only way I find to avoid this is to not just select “none” for a plug, but rather to first red-“x” it out and then it disappears and won’t show as blank. Then, “none” can be used. Bummer that Steinberg can’t get it together on that one. Maybe someone there will have the intel to achieve something smooth and not so annoying.