Changing the distance between bar numbers and the staff
You can change the minimum value for how far away from the staff bar numbers appear in each layout independently of other layouts. For example, you can position bar numbers differently in full score layouts compared to individual part layouts.
Procedure
Result
If you increase the value, bar numbers are positioned further away from the staff, either above or below depending on your setting for Placement relative to staff. If you decrease the value, bar numbers are positioned closer to the staff.
Note
This affects the minimum distance away from the staff, so bar numbers might be positioned further away than this to avoid collisions.