RobertJ made a version where the vectors glow, but it wasn't accepted by Mame devs 'cause, if I remember it right, it was entirely made on software (too cpu intensive). It probably would be accepted if ported to use shaders.
It's just a case of someone step in and do it (in a way that Mame devs accept it).
EDIT: I'm using it with this settings: screen resolution: 1600x1200 (2048x1536 would be better but I'd have to adjust my monitor horizontal every time); brightness: 1.00; contrast: 2.00; gamma: 1.00; draw antialiased vectors: on; beam: 3.00; glow strength: 350; bilinear filtering: on.
In my opinion is very cool, but I think it would be better with more antialiasing and more contrast.