FYI, I called Blitzsafe on the scrolling function. They are the ones that control the software interface to the head unit, not the XM direct module, as I initially thought. Anyway, I spoke with an engineer about its function and he said it was by design. They had to work within the constraints of the Sirrius architecture. Subsequently, when they were in development, they looked at the scrolling function and discovered that it would not word wrap properly on the 2nd line of the display.
The example he gave was that there is a 10 character display limitation. As an example, if The Beatles came up on the display, what would get displayed during the scroll would be "The Beetle" and the 2nd page would just have the "s", unlike RDS which would display "Beetles" on the 2nd page. They said it looked so bad, that they decided to only show the first line and not scroll.
However, something that they have that Sirrius doesn't, is the ability to scan via category (e.g. Rock, Jazz, News, etc...)
So, that is the skinny on the scroll function.