Derrida on Plato on Writing

Derrida on Plato on writing says “In order for these contrary values (good/evil, true/false, essence/appearance, inside/outside, etc.) to be in opposition, each of the terms must be simply EXTERNAL to the other, which means that one of these oppositions (the opposition between inside and outside) must already be accredited as the matrix of all possible opposition. And one of the elements of the system (or of the series) must also stand as the very possibility of systematicity or seriality in general.”

Especially the first part of that resonates and perplexes: Is it possible to problematize inside and outside without also “problematizing” the difference of good and evil, true and false? Do all binaries stand and fall together? Or is this perhaps Derrida still somehow in the grip of the structuralism that he’s overturning?