this was almost the exact thing I was cautioning in the other thread with the silly argument, except I was specifically referring to the screw holes rather than the other fittings. I was either unclear or others didn't understand, hence the silly argument, but there are pictures in the other thread of it working.
Glad to see that I'm not wrong and that is a valid concern.
There are other options of a DIY flavor which might be made to look reasonably elegant if done with some level of precision. For instance, you could manufacture your own sidepanel out of cut sheet steel, without the "folded edges" or "tongs" which fit in the case frame. You would simply tap screw holes in the case frame and drill looser holes in the sheet-steel panel to fit 6-32 screws or thumbscrews to secure the plate.
Or, you could use 1/8" or 1/4"-thick Lexan plastic to make the same sidepanel.
There are a lot of options and possibilities, some of which (as those above) would not require any significant modification to the original case and its parts.
At the same time, when I shop for a case, I try to imagine the various mods I might want to make, and figure the inconvenience of modding into my selection.