Do film makers/producers consider important that I was an actor in a film with famous cast if I'm a composer now? Could cause problems if I have both types of credits on IMDB?

[Daniele Nasuti]

I kept this secret for almost 15 years because it wasn't about music, but now I’m looking for interesting features, short and docs to score, maybe it could be useful. 

Before becoming a film composer I was a stunt double and background actor in a film with famous people involved.  The producer is one of Ferrari(2023) producers; costume designers also worked for Sarah Jessica Parker; I'm in several scenes with famous italian actors, and one of them collaborated with John Debney and Diane Warren. 

We have been together for a month so I could live the film making experience from inside, how it feels and how angry directors could become :D even if I was an actor and not musician (I was stunt double of a musician character anyway :) You can clearly see me in some scenes as myself and as stunt.

[PPNS]

no one gives a rats ass about anything and most people in the industry have side hustles to survive or pay the bills.

[Emanuel]

Sure, on the opposite. Right on the spot as @PPNS said :- )

[fuzzynormal]

Context matters in film production.  You have more context.  What you possess through experience is an asset.  --Might be a minor asset that doesn't really matter much, but it's certainly not a liability.

[Clark Nikolai]

Both types of credits on imdb won't be a problem. In fact it could show that you have experience on set so you possibly could have a greater understanding of a film project than just your one area.

It won't matter if there were some big names in the film.