Top Plate for Heavy Duty Shelf

I have some heavy duty shelf and wanted to mount one single wood panel over two of them.
But on top there is no mounting support and the top metal would be pressed over time into the wood. I used a caliper for measuring the dimensions. The dimensions for the shelf feet/top are outside 35 mm, inside 33 mm (begin of rounded edge) and thickness 2 mm.
I used Tinkercad to made me some top plates, here https://tinkercad.com/things/ihwzqjECMqD you can find the thing.
I made three Versions one without a hole, the second with a hole where you can use a washer and third with a milled hole, so you can use wood screws.