Hi!
I think it's just blunt damage that's broke right now. If you used spikes or axe traps, I think it still works. (Disclaimer: I haven't tried)
Personally, I stopped using stone traps back in the 2D days because if you have an individual within a group of hostiles triggering it, it would lure a random dwarf to their death as they went to refill the trap.
This being said, I have been a cheapskate using wooden spikes throughout the 3D versions, optimizing for injuries that did not kill instantly so the corpse wouldn't get stuck in my traps.
Experimentation in 31.01 against wildlife (mostly deers) have shown that you need on average about 2 or 3 fully stocked (10 spikes) weapon traps with menacing wooden spikes to kill a deer. Given the high number of spikes, I personally find the probability of serious injuries a little bit low, but not crippling so.
Using weapon traps with 10 giant axe blades or battles axes, I found that fatality occurred with one or two traps, usually with the first as legs or heads of animals got cut away.
In my personal opinion, it is good if the stone fall traps have been weakened. Unless you make it impossible for a creature to evade it, I would think that most animals would do fairly well to at least dodge most of it without getting insta-killed.
And given how much metal you find on your maps AND how quickly you can gain riches via the caravans, making traps using metal axes is not impossible.
Well, these are just my experiences and opinions.
Durin: Good luck! And I hope to hear the tales of your dwarves over in the Fortress mode section.
Deathworks