I propose a quick button that flips your sequece from either horizontal to vertical or from vertical to horizontal.
In sequence settings, there should be a button you can press on the Frame Size line that with one click -- swaps the frame sizes from vertical to horizontal. Perhaps if you click Horizontal the frame goes horizontal and if you click Vertical, the frame is then vertical.
I know we have Auto Reframe, but for what I do, it's almost more work to fix the auto reframe than it is just to manually copy and paste my vertical attributes to the clips in my sequence in one go.
And with everything I cut today, most of it ends up in the vertical space as well, so this is just a standard part of my workflow. Currently I just retype the frame sizes and move on (it works), but it just seems like such an easy fix to swap the numbers and the frame orientaiton in the Sequence Settings panel.
Atttached is a mock up of the Horizontal selection. Just a thought.