I suggest PS UXP maintainers add an API: layer.filter((x,y,c)=>RGBA(255,0,0,x/width))

The filter function executes its parameter function for each pixel in the layer. The xy parameter of the parameter function is the coordinate of the pixel, the c parameter is the original color, and the function value of the parameter function is the new color of the pixel.
This will be a very powerful function that allows developers to freely implement various effects, including but not limited to the current various filters.
The current applyCustomFilter is too weak!