By safely, I mean being sure that it isn't an operation that can cause performance issues later on, imposing a refactor.

An example of what I'm meaning (in a route handler):

import { headers } from 'next/headers';

const someFunction = () => {
  // ...
  const reqHeaders = headers();
  // ...
}

export const GET = async () =>{
  // ...
  const reqHeaders = headers();
  // ...
  someFunction();
  // ...
} 

I'm asking this because I'd choose this approach over sending a parameter every time.