How to programatically set appID for Maestro tests based on platform

Question

How do I change the appID based on a parameter passed on the command line when running Maestro tests?

I'm aware that it's possible to set the app ID for a maestro test suite based on an env variable (Is it possible to run a single Maestro flow against two different app ids?), but how can I programmatically set the appID based on a more simple flag as a parameter?

I'd like to be able to run tests with either maestro test . -e android or maestro test . -e iOS, and for this I'd need to take that parameter and use it to work out the appID string programatically in javascript (I think?).

I have a rough idea of the javascript code to do this (see below), but not sure how to pull the parameter for this:

output.result = function getAppId() {
  // Assuming parameters passed to Maestro can be accessed from command line arguments
  const args = process.argv;
  const isAndroid = args.includes("android");

  // Default app ID
  let appId = "com.ios.appid";

  // If 'android' parameter is present, change the app ID accordingly
  if (isAndroid) {
    appId = "com.android.appid";
  }

  return appId;
};