Reasoning for 1 week vs 2 week changes

Does anyone actually know WHY some of us get to change trays every 1 week and some of us change them every 2 weeks?

Sure, I know it is up for the ortho to decide. But how does an ortho actually make that determination?

Does the clincheck software help them decide some how? Does it make a difference on how the teeth need to move? Or are they just winging it and making shit up?

I know we aren’t orthos on this sub, but perhaps people here have knowledge from discussions they have had with their ortho.