This answer got me wondering, The Doctor spent seven years on Voyager and expanded out of his role to a significant degree, not to mention he is literally a part of the ship, so it would make sense that he would be able to accomplish many advanced engineering tasks on it, and if I remember he did actually perform some engineering work on Voyager. Despite that, did he ever actually mention any knowledge or ability gained from the grafting of the EMH Diagnostic program onto his?