I am curious to whether Chomsky has ever addressed anything about orthography, spelling or the impact of writing systems. The way I see it, orthography lies outside of Grammar in his theory. I couldn't find anything to support that, though. Has he ever written anything on it?
The first relevant work that I know of are comments for Project Literacy Meeting, Chicago, August 6, 1964, which was later published in Readings in applied transformational grammar, ed. by M. Lester (Holt, Rinehart and Winston, 1970). There were a couple of other works from that early era, viz ‘Some observations on the teaching of Language’ in The pedagogic reporter 21, no. 1 (September 1969): 5,6,13 and ‘Phonology and reading’, in Basic studies in reading ed. by H. Levin and J.P. Williams, 3-18. New York: Basic Books, 1970.
I would also recommend Chomsky & Halle The sound pattern of English. Although you can never be sure who wrote or most-strongly approved of what idea in that work, I assume that at least at the time this represented his feelings. There are numerous short statements about orthography. E.g. p. 49
Orthography is a system designed for readers who know the language, who understand sentences and therefore know the surface structure of sentences. Such readers can produce the correct phonetic forms, given the orthographic representation and the surface structure, by means of the rules that they employ in producing and interpreting speech.
This is not actually a "scientific observation", it is a philosophical idealization of an ideal orthography created by an omniscient being, serving to illustrate the point that variation in pronunciation maybe should not correspond to variation in spelling.