No, this is just discrete multitone. Leaving aside the issue of errors, it still takes you time to know the carrier is gone. You'd have much better choices about how to do this that are more spectrally efficient and equivalent in latency.

Reductio ad absurdum: if it were zero latency, you could turn on and off the signal infinitely fast, and then send an infinite amount of information across a narrow channel.

> This proposal is for a 50 kHz system, so if they used bandwidth in the same way, that would be 100 carriers sending on/off commands and/or combinations.

Yah, or broadly: it's like OFDM. You don't have to constrain yourself to one bit per carrier, and you can use error coding across multiple carriers, etc.

Also important to consider authentication...