> creating a similar effect in some cases to the desired one, but likely less effective than a row-column or other 2D approach I have actually implemented and

> creating a similar effect in some cases to the desired one, but likely less effective than a row-column or other 2D approach I have actually implemented and tested a 2D overshoot, and it gave worse quality/filesize ratio. Perhaps by accident (or less obvious correlation), but this order seems to give most compressible pattern.