polygon mask soft edge dependant of resolution ??

Hi,
The soft edge parameter in the polygon node seem to be dependant of the horizontal resolution of the source.

If for example i create a 10x100 background, I can create a mask with a Soft edge grading from the top to bottom of the shape... very odd.

In the screenshoot below i show the problem with a soft edge of 1.0 (maximum)
Is that normal ?

Type a higher value in the numeric text box.

Nope, text box is lock to 1 here !