The L brackets are useful
Those brackets are handy - - they can be used to anchor other modifications. Our cargo net is attached to them, and our blackout curtains hang down from them. It is very easy to round off the sharp corners of the brackets with a flat file or even a random orbital sander, and it is fairly easy to drill holes in the brackets if needed. I think they are aluminum, if I recall correctly. Steel is much harder to drill through.