My visually flying across the trail of another aircraft 1nm behind and 100ft above is not dangerous
Assuming you are VMC and have identified the correct 'target'.
How do you know there's not another aircraft nearby?
I always remember that separation standards are minima and shall be increased when requested by the pilot or considered necessary by the ATCO.
Putting two aircraft parallel with minimum separation in weather avoiding situations can result in the controller having to explain on the MOR / Airporx report why they thought it was safe to apply the minima in that situation.
You really don't have much grasp of the route structures within the LTMA if you believe we have room to apply more than the minima.