I expect unless the flight is very empty, that the empty seat would then need to be between status passengers.

Currently:
A gold is booked in 37A
Another gold is booked in 38A
Passengers choose freely around these seats, allowing two couples to choose 37BC and 38BC

Proposed system:
A gold is booked in 37A. 37B is then blocked.
Another gold is booked in 38A. 38B is then blocked.
The two couples previously sat in 37BC and 38BC are displaced.

Possible other system.
A gold is booked in 37A. 37B is then blocked.
Another gold is booked in 38A. They are moved to 37C next to blocked seat.
Only one couple can sit together.

My questions as follows:
* How would 38A feel about being moved to 37C with guaranteed 37B. From what sunrisegirl says above, passengers tend to hate being moved.
* How low would the occupancy to gold card holder ratio need to be before seat blocking became prohibitive to other passengers and their seating choice. My suspicion would be that on the majority of British Airways domestic flights to Glasgow at least, seat blocking wouldn't be possible at all on most flights as they are all so full!