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Hello, okay so if you were going to set a canonical I'd set it on DE as you're redirecting the traffic to that page anyway. The schema You can declare the language and to a degree target country using markup which can aid in understanding of your site with search engines etc. Sorry just saw the edit, yes i can image structuring your site that way will do the job too and avoid the whole issue. Hope that helps. Seems like you some what resolved it your self