Curious to see what my teacher said about him, I picked up Precious Teachers: Indian Memoirs of an English Buddhist, and read the last chapter about Dilgo Khyentse.
As the movie points out as well, he always made people feel welcome, and Sangharakshita felt welcome when he visited him. On the 9th of May 1963, Sangharakshita received the phowa or 'conciousness tranmission' of Amitabha, an oral transmission of the Nyingmapas. Dilgo Khyentse visited Sangharakshita's vihara in Kalimpong, and later gave him the Kurukulle sadhana, the dancing red form of Tara, that same year. Sangharakshita was guided by Yogi Chen to seek these out, and you can read all about why in Precious Teachers, and the circumstances of those times in Kalingpong.
In Moving Against the Stream: The Birth of a New Buddhist Movement, Sangharakshita writes that Dilgo Khyentse came to Kalingpong in 1959. He adds that he got the Jhambhala sadhana, which he didn't directly state in Precious Teachers, instead saying it wasn't really Buddhist, that it was more Bon.
When Shangharakshita was planning to return to England permanently, he went to get the blessing of Dilgo Khyentse, who was then living in Darjeeling in 1965 (p.360).
I know I can flit from one text and teaching to another, but I really think I should read Dilgo's books and read more about him. He seems like a really warm human with a deep practice and lots of knowledge about the tradition. I did really enjoy The Hundred Verses of Advice: Tibetan Buddhist Teachings on What Matters Most (Shambhala Pocket Classics).