Who was "Derol"?

Question

Throughout Glass Onion, we see a disheveled man whom Miles calls "Derol" whom he claims to be "working through some things," and who has minimal interaction with other characters. However, he does not appear to be involved in any of the intrigue, and Benoit Blanc does not mention him in his summation of the facts of the case.

Of course, in terms of the murder mystery and thus the main plot, Derol may be meant as a rather obvious and humorous red herring. Still, one way or another, Miles still had invited him to his very exclusive private island and let him stay there during his event, so he presumably meant something to Miles. In short, who was Derol and why was he on the island?

Answer 1

Derol is mainly a comic break

he really is just a random guy living on Bron's island. Besides being there for comedic effect, Derol acts as an interesting red herring for the greater Glass Onion mystery. He randomly pops up at key moments

And actor plays in all director's movies

Derol is played by Noah Segan, who appeared in the Knives Out cast as the over-eager Trooper Wagner. Funnily enough, he's also been in every single Rian Johnson movie in one capacity or another

Side-note: Glass Onion movie is more of a comedy rather than a crime mystery as the first Knives Out movie was.

Johnson really works to keep an undercurrent of jokes flowing throughout the whole movie