Anyone read Bridcut's comments on the forum and watched the film? It was Ken Russell's film (his masterpiece) which first made me aware of Delius's music many years ago when I knew only The First Cuckoo and I've become more enthusiastic with age and now have recordings of most of his available output. I enjoyed Bridcut's film with very enthusiastic support for the composer from Mark Elder, Andrew Davis and Bo Holten with the latter's Danish orchestra providing the musical excerpts.
Elder described Delius as difficult to conduct and Holten commented that he thought English orchestral players disliked playing Delius! The composer does seem to be very divisive and the programme acknowledged Beecham's promotion without which Delius's music would have been very little known. What I didn't realize was Delius left little in the way of interpretive comments on his scores and much of what we hear today is based on Beecham's annotations.
Enthusiasts or potential converts who didn't see it check out the programme on the I-Player.