Location Control can't be globally disabled, or the scanner would try to scan the entire main database when it's enabled.
You can set up location presets to tell the scanner where it is when no GPS is connected. If your FL covers a large area, enable Location Control in the FL, and use location presets to tell the scanner which part of the FL to scan. If your FL only covers a small area, turn the FL's location control off and only listen to the FL when you are in the coverage area.
There's better ways to accomplish what you're trying to do, What you're proposing would break the scanner if monitoring the Main Database was enabled.
You can set up location presets to tell the scanner where it is when no GPS is connected. If your FL covers a large area, enable Location Control in the FL, and use location presets to tell the scanner which part of the FL to scan. If your FL only covers a small area, turn the FL's location control off and only listen to the FL when you are in the coverage area.
There's better ways to accomplish what you're trying to do, What you're proposing would break the scanner if monitoring the Main Database was enabled.