Another consideration is the location of the "excess". If it's going on a door, trunk lid, or hood that is going to see some slam closing (especially given the extra weight), then try and limit the filler in these areas.. Here's how not to do it, This picture is from Old Soul Speed & Custom on IG, they are now fixing someone else's work... also note the thickness at the door edge. They said in the thickest area it was 5/8 thick.
