CKEditor handles the position of the dialog correctly even if the viewport is smaller than the dialog.
The problem was that the initialization of the footnote's CKEditor changed the height of the dialog after the dialog's layouting. If that happens, a re-layout of the dialog is necessary to fix the position of the dialog.
Regarding https://github.com/andykirk/CKEditorFootnotes/issues/12
CKEditor handles the position of the dialog correctly even if the viewport is smaller than the dialog. The problem was that the initialization of the footnote's CKEditor changed the height of the dialog after the dialog's layouting. If that happens, a re-layout of the dialog is necessary to fix the position of the dialog.