LF Glow internally uses Screen blending. To get an "Add" mode glow, set the "Mix with Original" to 0 , then use the Blend Modes dropdown on the layer itself to change from "Screen" to "Add". This creates a much hotter, overexposed look.
Search "Lucas Frank LF Glow" or check AEScripts / GitHub. lf glow after effects plugin
Here is everything you need to know about this plugin. LF Glow is a fast, anti-aliased, 32-bit linear light glow generator. Its core philosophy is "clean, controllable, and fast." Unlike standard glows that blur the entire image (including blacks), LF Glow intelligently isolates highlights, applies a directional or radial blur, and remaps the result without destroying your original luminance values. LF Glow internally uses Screen blending