Can't weather change be only cosmetic without actual time passage? For example even an option in the settings in which you could choose to enable and even set a time for irl time passed for the cycle. For example I'd like a 2 irl hours playing the game to be a full cycle only to get from dawn till dusk, and some weather like rain or snow in a random amount of time.
I guess that's exactly what didn't work with the how the engine tracks time in contrast to how system time advances.