One practical advice, that I would like to have on such plate:
Make another hole in the most rear part of the plate in the middle. It is functional when using elastical straps or net. I like to attach it in the midle in the rear also, so I am sure nothing will get loose or lost when having luggage on that plate. I ussually put on top of dry bag my Teva sandals, plastic bottl of water... shirt or towel that can dry while riding...
Such stuff can slip back and fell off, that is less likely to happen if there is attachment on the rear also, not only on sides.