Update.
Run many presets, all executed fine except those with ALPHA ("execution error").
Here the zipped program updated (not cleaned).

Info:
the 3 presets with alpha, whiich terminated in error, are:
Bronze
Elegant
Night View

Run interactive "seem" to be working (but the "alpha" curve is not shown)

PS: 2 of the 3 have "curve type free"

Forget my last comments on execution error if preset with channel alpha:
- I simply did not add alpha to the layer
Done, it works also with channel alpha.
Sorry...

filter updated with the "add alpha"



from this one, whoever interested can personalize own module (I did it for myself, cleaning the code and adding a few "bits and bytes")

Thanks again a lot to ofnuts, tin and teapot for having built this process for me.