G'MIC's preview is different from what is rendered

I suppose what @Jai_Guru wants is a preview mode that uses the full image area, even if it’s slow and computationally expensive, in case of scale-variant things like this.

So that the filter effects can actually be previewed without having to go in and out of the dialog box.

(this is part of why I’ve made Filmulator always run on the full resolution, even though it’s perfectly scale-invariant)