The pop-out ignition switch is one of the most fun and fascinating things about the Model A.
There is plenty of information about them - and worth a read. I chose to replace my replica non-pop-out with an original of the right year. First, you may be sacrificing the accessory terminal on the replica. Second, the correct length of the armoured cable leading to the distributor is very important. Third, the pop-out may need easy but careful restoration to ensure that it is reliable. Fourth, check the inside of your instrument panel to see if it is original. Many had the pop-out flanges or lugs cut off to accept the modern replica switch.
An original pop-out is very satisfying. Turn the key and the button pops out. Remove the key and drive away. Push the button in to stop the engine. Cool.