Individual texturing requires matching filetypes

[cozyton]

When replacing a frame from a UI spritesheet with your own texture, it will not work unless the filetypes match. This would usually not be a problem, but when trying to use animated webp textures through ImagePlus it becomes a little limiting.
Maybe a .json file using the name of the frame you are replacing could point towards the new texture to use without having to specify a node, since preserving that functionality would be important.
You could use this to create animated UI elements, alongside maybe even icons?

[Alphalaneous]

Technically speaking, you can rename the extension to .png and it will still point to the right one even if it is a different file type. Though I do wish to eventually add a way to define a texture map