Game Mode's construction script/event begin play NOT invoked in Simulation mode?

Is it is expected that the Game Mode won’t run its ‘Construction script’ or even ‘Event begin play’ in simulation mode? (works in PIE)

Recently I moved most of my global data to a custom game mode for easy access (eg: this contains a list of AI units in game, a list of human units in game, etc).

As a workaround I’ve changed my design to push this data from the event begin play of the pawns to my game mode BP instead. This works in both simulation and PIE, but is it a bad idea in the first place to use Game Mode to store this kind of data? I’m now considering using the ‘global engine singleton’ to store a static gameplay data class which will have all this info. Not sure if overkill…