Edge detection speed is not equal in all cases

[DataGridXL]

Edge detection is too fast in grids that have only rows to scroll, compare to grids that scroll in Y and X directions.

Edge detection in a grid that scrolls both directions is nice and steady:
https://datagridxl.com/demos/one-million-cells.

Edge detection in a grid that scrolls only rows is too fast:
https://datagridxl.com/demos/array-of-arrays-2d-array

The "Sorting Columns" demo even does native edge detection when mouse is close to window edges. This native edge detection scrolls the window. Should be disabled in case mouse drag started out of DGXL instance: https://datagridxl.com/demos/sorting-columns