Thank you for your response, Kainscalia.
I'm not sure what permission you're seeking from me. If you mean quoting my previous post here, none is required as this is a public forum. If you mean quoting from my previously linked S&F article, consider permission granted as long as proper attribution is given.
As I previously remarked, this whole business has long been a matter of concern on S&F, consequently there are a large number of articles therein dealing with the problem, almost all having to do with the operas and music-dramas of Richard Wagner as along with the operas of Mozart they're of special interest to me. One S&F article ("On Interpretation", which 2004 article can be read here) deals in a general way directly with the problem of creator intention in performed works of art as remarked on above by you. As I wrote in that article (from which article, as with all articles on S&F, you're also given permission to quote with proper attribution):
As regards your,
I've often quoted on S&F what I'm pleased to call The A.C. Douglas Opera Director's Prime Directive: "Thou mayest do any bloody thing thou wilt in order to realize a dramatically and aesthetically evocative translation of the score (music, text, and stage directions) of the opera into its concrete physical form onstage so long as what thou doest is at every point consonant with the score and contradicts or diverges from it at none."