I’m back with an update from our developer. Here is his feedback.
This code snippet const editorSection = this.checkEditorSection (); is used in the selectEditor to define the overlay that the editor should be displayed on, that follows top, left, bottom, top-left-corner or bottom-left-corner. This is why we need to set the correct z-index .
Let me share an example that explain how it works. If the Client use fixedColumnsLeft: 1, they would receive left and if they are not using the Fixing feature they are left with an empty string.