As I am developing neumann (periodic), and neumann (mirror) row/column shifting for non-isometric tiling tool, I realized two box would be very helpful. One for creating command not used anywhere in .gmic or in any .gmic file, and then the other box is for testing the command. By having two different box, I can manipulate one of the box for the developing command, and then check output using blending mode like xor to tell if they’re valid. I’ll admit, this is a obscure case where this would be useful. I’m not sure how useful it would be though, but it does make it easier to compartmentalize.
I tested that, and it seem to work. I don’t think I have tried something exactly like that, but perhaps something similar, and it didn’t work, and I don’t remember what I did. Thanks anyway as it works as I want.