In old ExtJS 4.2 days, we used to rely on initComponent method for initializing the component such as storing non-primitive values and handling localized texts. (We replaced the i18n block in the class at the constructor, and used it in initComponent which gets called after constructor).

But now with ExtJS 6.x that uses MVVM, I think I can achieve the same using ViewModel.. or even init function of ViewController.

I am just wondering what's the best practice that Sencha recommends.
Or is this just a personal preference thing?