No experience with CDI, but for a typical ignition coil, + from battery and - to points or ignition module, ground the - through a not-easy-to-find switch. With switch closed, it is the same as points/module not opening.

I did so on my 1973 V8 powered Datsun PL620 in 1982, as I figured insurance would not cover my "investment" in a new out-of-the-crate 350 cu in Chevrolet V8, Hooker solid motor mounts-fiberglass firewall and headers, rebuilt turbo 350 trans with shift kit, shortened and resplined Ford differential, custom drive shaft and all the externals to a long block (Carter 500 CFM AFB carb, aluminum high rise intake manifold, starter, alternator, etc) plus new exhaust system.

For a CDI system, probably easiest to do the same as adding a tether/lanyard switch to duplicate the stop/run switch, but instead of the tether, hide the switch.

 

This is not an ignition lock.

This prevents shifting into neutral keeping it from being rolled away.