category filter causes page to "jump" / "flicker" on mobile causing layout shift

[Horizon]

Maybe another way to do this is to change the flex order by adding order 2 to the left column when on mobile to move it to the right which becomes below the body.

Then the layout shift becomes near zero on mobile and the mobile page performance report really increases.

And no layout shift viewing on an android phone.

Only problem is category filter then ends up a the bottom of the page, so the mechanism the splits the second-copy left aside would have to be changed to move the filter to the top (display:none in css to hide by default the content of the filter box.)

I think this would work, but might require a customization to figure out the javascript change.