Your comments

Thanks for the links - (and BTW, thanks so much for the incredible amount of work and commitment you are making with shader forge!)  My issue with easing or interpolation is that it will always bring the scrolling back to 0-1, whereas my understanding of a scroll depends on numbers continually climbing beyond 1.

It works - with the insertion of frac, but, of course there is the irritating and unusable "reset" that occurs.   Interestingly, the current network works for a couple of seconds on very low values of u&v after opening sf, but after it has been open a while, then it reverts to the behavior that I described above.  So - you're right about t.  It does seem, however, that smooth scrolling noise across the two axes becomes much more difficult in this setup.  Is there a way to get a Time.deltaTime equivalent?
I mean a bit like being able to construct Vector constants from inputs rather than numeric values.  I understand Append can be used to do this, and constants are no-clutter, but it's rather annoying to have to create 2 append nodes if I want to be able to "splat" or "swizzle" a Vector3.
I second this.  I think it would also be useful for creating value, vector2, 3, 4 nodes, which currently require you to manually type in values.