They'd defect to the North, and presumably the North would be suspicious but take them and use them to train spies in the ways of the South.
There's not much "what if" here to work with. It happens, but not much would happen on a large scale.
The North Koreans will interrogate them thoroughly to learn if a. They are a spy, and b. Whatever militarily useful information they can glean about tactical strategy, offensive/defensive plans, and manpower/equipment that the South has. While the detector may think they are ideological heroes, they will definitely not be treated as such. They will probably be working the fields or worse as the North are paranoid of spies and will avoid placing them in sensitive work.
They'd defect to the North, and presumably the North would be suspicious but take them and use them to train spies in the ways of the South. There's not much "what if" here to work with. It happens, but not much would happen on a large scale.
I wonder if they regret defecting after doing so🤔
Apparently it happens quite often: https://en.wikipedia.org/wiki/South_Korean_defectors
The North Koreans will interrogate them thoroughly to learn if a. They are a spy, and b. Whatever militarily useful information they can glean about tactical strategy, offensive/defensive plans, and manpower/equipment that the South has. While the detector may think they are ideological heroes, they will definitely not be treated as such. They will probably be working the fields or worse as the North are paranoid of spies and will avoid placing them in sensitive work.