Blur get value from one blur value if the item has a filter with it

Hi, following the function "modify_filter_gaussian_blur_from_item" inkscape reads the blur value form the first blur primitive happends in the filter applied into a item.

In my opinion this is a bug, I try to explain:
One filter can have more than one blur primitives and only take first at account.
The blur applied could give brong global blut to the item if after first blur there is others primitives that changed the expected blur resulr

In my opinion we need to refactor this code, for example defining global blur and global blending primitives as oprional last and before last primitive to easy change blending and filter to all items having or not having filter with the same result.