Are Rings of Feather Falling useless for Flying Constructs?

[unseenmage]

I've built a gaggle of flying Effigys each with an Item Familiar Ring of Feather Falling.
It occured to me today that, as constructs, they're probably already immune to most (if not all) of the status effects that would provoke use of the Rings.

Are their Rings useless and if so what 2,000gp item would the Playground suggest to replace them?

[Flickerdart]

They're not immune to stalling (unless they have a high enough maneuverability) meaning that a Solid Fog or similar takes them out with no save. If you spent a lot of money on them, you might as well put down another 2 grand to keep 'em a little more safe.

[Crake]

They're not immune to stalling (unless they have a high enough maneuverability) meaning that a Solid Fog or similar takes them out with no save. If you spent a lot of money on them, you might as well put down another 2 grand to keep 'em a little more safe.

Also if they fly via the use of wings they can be tripped (or grappled/pinned) into a stall which could be nasty. Either way the ring of feather fall will activate regardless once they start falling.