I think I see what you've done, and it's quite cool. I can imagine lots of uses for it. It's just that it's not what other programs would call "feather". Instead of feathering a selection, it's feathering the edges of a hole (by a fixed amount) that's already been cut in the layer.
I'm trying to be able to select an area of a layer (with any of the selection tools), then transform the selection by applying "fuzziness" to the selection's edges (not to the actual paint's edges), in varying degrees based on the need. That way, I can then go make an adjustment (like levels, brightness and contrast, etc.), and it will affect the fuzzy area, with the effect becoming less toward the edges of the selection based on how many pixels of fuzziness I asked for.
Also, being able to "feather" the edges of the brush would be useful.
If you aren't familiar with these features, Photoshop has them, as do Gimp and Pixel.
In any case, thanks for the plug-in!
Does anybody know if feathering "a la Photoshop" is a planned feature?
-Mark