I have been trying to figure out this tree. The foliage is good for animal consumption, but the seeds are not. It is actually a mystery how they spread according to
this article. I would guess a couple things based on this:
1) the seeds are not intentionally eaten by mammals, but must be eaten and moved around by something. I'm assuming they are unintentionally eaten by bigger mammals but who knows, they have a really tough cover that may resist degradation in a ruminant gut.
2) The pods are likely the target of the ruminant, like honeylocust. These are slurped down by deer, they barely chew them.
3) The toxicity is likely overrated, like black cherry. This
resource for silvopasture from USDA recommends it. Animals will eat all manner of toxic plants if they are starving. Don't let them starve. Most plants that are really toxic have aversive qualities. I have Digitalis in my silvopasture, black cherry, and other toxic plants.