Northwest only axle alignment?

I have a Forest River Rockwood with torsion axles, and after two "alignments" at two different shops, a third shop told me these axles can't be aligned. This was a major shop that aligned semi truck and trailer axles; the tech took me into the pit to show me why there was no way to align the axles on my trailer.

I haven't worried about it since. When the tires wear, I'll replace them.