Does anyone know of a roller shade of decent design that will stay on
track and not shred upon use?

Presently the only inexpensive roller shade that I have been able to
find is the type that is inherently flawed. First the width adjustment
is accomplished by a telescoping tube that creates a dissimilar
diameter. That in turn causes the blind to be biased and move to the
smaller diameter side. Secondly the design of the shade also includes
shade material that is intentionally weakened at vertical fault lines.
That is included in the design so that one can easily tear a vertical
slice off to accommodate the correct width.

When you have both diagonal roll up and a weakened material you get
shredding at the smaller diameter side. The shade is worthless. It
seems that self installation ease outweighs usefulness. What a joke.

The older type of roller shades were cut to length on a lathe type
machine. No fault line material. No uneven diameter tube. It actually
worked without shredding or shifting.

Who makes a properly designed simple inexpensive roller shade?