I'm looking at a bookcase design that has a platform constructed out of 2x4's, which is shimmed, and then the bookcase rests on top. The trim hides the plinth.
I'm not convinced of the utility of shimming the hidden plinth as opposed to just shimming the bookcase itself, then attaching the trim. If the platform is smaller than the perimeter of the bookcase, then the entire weight is supported by the bottom shelf, which isn't good. It really must be exactly the same dimensions as the bottom of the bookshelf and thus seems to add extra work without benefit.
Am I missing a potential benefit?
Thanks