In answer to the question of dangers, the answer must be unequivocal: Wilfrid Mellers does have a distinct voice, has produced music of importance and has avoided mere faddishness.
In order to prove this with any degree of finality in the public forum, it would of course be necessary for the works to be widely available in modern recordings and published in a complete edition. But in the meantime, armed with the extant scores and a recent recording it is possible to form a clear idea of Mellers' distinct genius.
As befits a man of such wide intellectual culture, Mellers' music has been influenced by philosophy and Jungian ideas. For example, the Opus Alchymicum for organ -- recently recorded by the brilliant Kevin Bowyer -- takes up the principles of alchemical studies interpreted by Jung as a starting point for musical processes. Mellers writes in a preface to the work which was composed in 1969, revised in 1972 and revised again in 1995:
From the depths of the cluster chord come sounds distant and yet secure: fourths and fifths. The mood is mysterious and pregnant with potential. It is also perfectly fitted to the ancient alchemical doctrine of the golden tablet of Hermes Trismegistus, the primary source of alchemical teaching according to the best traditions: 'As above, so below.' Out of the primal matter - the cluster chord - come the invertible intervals of fourth and fifth. We may comment on the Pythagorean mathematics of it, the quiet reference to the Semitic Deity's reflection upon the waters of chaos, the mirror image of the inversions, the alchemical process of transformation from the earth (the chord), the play of reality and its multitudinous phenomena upon the basic 'ground' of Being and the source of consciousness itself. Given Wilfrid Mellers intellectual arsenal these are not gratuitous suggestions - rather they are likely both conscious and unconscious influences upon the organic seed of the work. Altogether the effect is magical. And so begins a 'magical' - in many senses of the word - composition.
When illumination comes it comes with power and grandeur, wild abandon and the absorption of all elements into a new alloy.