Exactly, you should worry about design, not about one empty class. Otherwise you should stop using any Lists and especially Maps It is not “a huge overhead” it no practical overhead at all. On your app initialisation even before any UI you create hundreds and thousands classes with state (not just empty, like in you case). Overhead is so small that no reason to worry about it in such case. Spend your time to solve real problems and do real optimisation rather than worry about one global object

yes, that is absolutely true

If this is screen related why it should be an

object

instead if just member function of your screen or one of your classes. You probably also don't want to expose those screen specific methods