The reformat widget is not very powerful and I don’t think it supports suchorthogonality constraint.
Instead, you can rotate slice views by displaying slice intersections and then:
- use Ctrl + Alt + Left-click-and-drag using your mouse, or
- pinch-and-rotate on touchscreen (on Windows) or on the touchpad (on macOS), or
- or define the desired orientation using a transform and then use “Volume reslice driver” module in SlicerIGT extension to show orthogonal slices
There are specialized modules for orthogonal reslicing along curves, etc.