I think all these remote units share a range of codes matched to the receiver unit. So if you lose the remote, you need to replace the receiver unit.
On the plus side, the range of these remotes is only around 15 meters. But I too was worried about someone using a remote with the same transmitter ID, so the isolator switch also cuts power to the receiver.
I took the cheap option if the winch isolator switch, i.e. the +12v wire to power the heavy current solenoid pack was re-router to a switch inside the cabin. This +12v line also powers the remote receiver. So when the switch is in the "off" state, the solenoid pack cannot operate, and the remote receiver is not powered.
Technically it is still possible to operate the winch by shorting out the right pins on the winch, but 99.999% of people would not know how to do this (and I've already forgotten which ones to connect to earth, and which to +12V).
But the remote unit is so handy, I've never used the supplied cable plug-in controller that came with the winch. They are brilliant for pulling in the cable/rope to the point just before there is tension on the rope while you are still outside the vehicle, and sometimes 10m in front of the vehicle. Very handy to see of the rope will rub across rocks or something else.












