Altered in what way? My saddler has adjusted the flocking in mine a few times as Genie has changed shape, but if you mean adjustable gullet like the Wintec saddles, then no.
Actually yes they can be adjusted for width! I have had two different Ideal saddles adjusted - one squeezed a bit smaller and the other the tree was widened to fit. No, they don't have an adjustable gullet like a wintec. But according to my saddler, they can go about 1 1/2 widths either direction.