[Q] Cannot configure deploy for 2 different hosting sites

https://github.com/angular/angularfire/blob/72d3c2e26ebd7ff367f250e74aa076cc3bd3cc40/src/schematics/deploy/builder.ts#L32-L34

The above piece of code prevents me from applying different configurations, so that I could invoke `ng deploy -c="development"`.
My `angular.json` config looks like this:

```json
// angular.json
"deploy": {
"builder": "@angular/fire:deploy",
"options": {
"prerender": false,
"ssr": false,
"browserTarget": "client:build:production",
"firebaseProject": "my-project"
},
"configurations": {
"production": {
"firebaseHostingSite": "my-project-prod-version"
},
"development": {
"firebaseHostingSite": "my-project-dev-version"
}
}
}
```

What was the reason to use only the default hosting site and throw error when I want make some changes?