I have a document that includes hundreds of small shapes, and would like to select a subset of them by holding shift and drawing two or more rectangular marquees to build the selection. In Inkscape, when you hold shift and select with a rectangular marquee, a union is performed between the current selection and the shapes within the marquee. In Affinity Designer, the selection state of each shape within the new marquee is simply inverted. The Affinity Designer behavior leads to problems if there is overlap between the two marquees, because shapes in the intersection are left out. I think the more common use case is that users want a union of the selections, not exclusive-or (XOR). To preserve compatibility with deselecting individual shapes holding shift, the shift-marquee selection could work so that if all items within the marquee have "selected" state, then they are all subtracted from the selection. Otherwise any "non-selected" shapes inside the marquee are added to the selection. This would make the single shape shift-selection a special case of the general logic. Alternatively, shift-marquee could always be additive, and a different modifier combination could be used for subtractive marquee selection. Thank you for an excellent vector graphics software!