Model within a model

Okay. It looks like that this is not an option what I'm asking. But how about I include the model every time there is a new function inside a model? Is this oke or will it also eventually give a memory leak if there are to many?
For example like this:

PHP Code:

namespace App\Models;
use CodeIgniter\Model;
class Settings_model extends \App\Models\BaseModel {
    
    function tempFunction(){
        $this->Users = model('Users_model');
        $users = $this->Users->get_all_users();
    }
} 


PHP Code:

namespace App\Models;
use CodeIgniter\Model;
class Users_model extends \App\Models\BaseModel {
    
    function tempFunction(){
        $this->Settings = model('Settings_model');
        $settings = $this->Settings->get_settings();
    }
} 


I know that this means that it includes a model everytime in every function, but at least I can get the application running on CI4 and I can fix parts in the future.

By the way, why is the autoload for models from CI3 gone? I have some applications having a lot of models inside the autoload and it still runs really fast. You did not even notice it when loading it.