I'm not familar with them on a Kubota however, if memory serves me, our IH has them.
I was thrilled at the idea of finally having a tractor that had them (I love the idea) however, we got a pull type 10' Rhino and since that is the only use for this tractor, I have no use for them.
The sick irony is, the smaller IH that we have (with multiple 3pt impliments) doesn't have them.
So the machine where I use the 3point does not have telescoping stabilizers and the machine that does have them.... we don't use them.
Just my luck