Since my mum passed away I've had no need of the panniers (for shopping). A flat tyre also prompted me to remove the Krauser mounts. The top box (barn door, pizza delivery etc) wobble also told me to try something else. So i now have a Motorworks folding steel rack that attaches in a much more sturdy way.
The rack itself is pretty carp. Whoever welded it does not know what a square, jig or ruler is
It also does not fit SWB bikes like mine despite using the 'my bike' filter and reading the words. Anyhoo, cutting 45mm off the overall length, fine adjustments with a big hammer, some welding and use of measuring tools means it now fits. It is quite sturdy and does not flex around like the plastic Krauser on spidery metal brackets.
Testing on the A1 with my 500lb laptop bag (seems like it!) bungeed to it whilst overtaking lorries confrims no 'fishtailing'. It mounts just beyond the seat, rather than hanging out back. So i will bolt the pizza box up to it, see how that goes and report back