Is that possible, given that you only have two feet?

Are you looking for a mode which allows you to select a chord rather than just a single note? (One foot for the root, and the other selects single/major/minor/etc)?

I've been looking at accordion keyboards - with the accordion layout you get 100+ buttons and you only need to push one to get a chord. However at the width of a foot that is too big, and so I'm not sure if I take a simplified layout or just a smaller version of that.

Yeah totally get it. You'd almost need a "mod" key or a wireless controller to turn on a chord mode similar to how arranger keyboards work...