I'm trying to scale a layer but would like to use a different center of transformation from the default which seems to be the top left corner (or another corner if the handles are used). Even if I could scale (interactively) around the center of the layer would help. Best would be if I could scale around the top center of the layer/image.
This is quite basic but I couldn't find any hint in the Gimp help, nor searching online on how to do this. Generally, when I need help with Gimp and search the document and online, I most often end up with no answers at all, even about basic things like this one. In contrast, when I need help with Blender, I can find what I need in a very short time. Is there really no good documentation for Gimp or am I missing something?