Does "surefooted sigil" amulet and passive "freedom of movement" stack?

Only on a corrupted item on the trade side it says "allocates freedom of movement" - which would mean "not stacking"

Does it stack normally?

The effect of the amulet and the notable passive do stack, yes. You'd get 80% increased evasion after rolling.

When you see the "allocates X" on an amulet, that's referred to as an annoint. You can use one of the distilled emotions to open a window that lets you add 3 distilled emotions and a necklace to allocate a notable passive even if it isn't connected to your tree. You can hold alt when hovering over a notable in the passive tree to see which emotions you would need to annoint that specific notable onto your amulet. Note you currently can't add or change an annoint on a corrupted item.

Now, if you have "Freedom of Movement" on your amulet, and you put the point in on the passive tree: that does NOT stack. You can't have that same node allocated twice.