I'd like to be able to essentially remove an item from the layout and invoke FileMakers's Slide feature based on conditional formatting.
anchoring and auto-sizing is not linked to conditional formatting at all. There is a filemaker GO trick that does what you are noting by rotating between landscape and portrait,
As far as I know, you can only cover/hide objects with conditionally formatted blank text boxes, not actually have an adjacent object expand over to hide other objects.
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