I suppose it adds a nice extra touch, but since the speaker is neither among the predecessors of the "thematic person", nor was he ever one of the "hidden thematic nine-letter word", it seems like something added to make the puzzle more difficult. Not that this is too much of a problem, and the misprints were in general well-hidden and well-executed. I would have liked, perhaps, something from the quote to be more directly applicable to the unclued entries rather than tied into the person revealed by the omitted letters in wordplay.
For whatever reason I was slower on the uptake than I might have been, though. I think I was just expecting more "two missing letters" clues than was the case so didn't bother to check what they were spelling out.
Possibly I'm heading close to Z Cup contention by now. Having checked the bottom-left corner more thoroughly I can see it's totally justified by Chambers. Perhaps a surprise that the word (a variant spelling) doesn't come with a different pronunciation. Since that's hardly Pilcrow's fault I'll withdraw that particular gripe! The unclued entries do raise a smile now.