Well, now that you have a keyed ignition, I guess your bike is safe from theft!!!
If you're not using a chain & lock, you're risking having your bike stolen, with or without an ignition switch. They can just pedal off.
If you are using a chain and lock, do you need a key ignition?
Any thief would just pedal off, then sort out the hot-wiring later.
Waste of time and effort, in my opinion.