GPencil: build with gradient opacity for fill material

My request is to have a object and gradiend distance parameter and raduis parameter for opacity ( and why not for thickness,smouting and simplify modifiers option or as influence depending on how modifiers. )

this feature will allow to make a gradient opacity with distance depending on raduis and selected object for example to build GP text that written by fill and stroke material, in order to make the stroke(outlineof the letter) builded first then make the fill gradually appear and that for every letter for the text,for visual example see this video first 3 seconds youtu.be/c9EijUTTTY0

maybe making build modifier fade affect fill material also resolve the situation