Adjust global navigation speed?

I have noticed that when the scale of a model changes drastically, certain navigation functions like walking behave differently: They speed up when adding a large landscape around a house, for example.

Now that I have purchased a 3D connection SpaceMouse this becomes a real issue because one model behaves normal, while another model (with large ground plane for preview renders) makes the navigation way too fast.

I know I could change the settings of the SpaceMouse, but this would mean I have to change this every time, and also does this probably alter the precision.

I have tried hiding the landscape but this does not alter the speed of moving around. Only deleting it does.

I hope this can be changed…