So I look at this https://metacpan.org/pod/Mojolicious::Lite#WebSockets it says $c->on(json as in a request of content type json
https://metacpan.org/pod/Mojolicious::Controller#on confirms
# Receive JSON object via WebSocket message as does https://metacpan.org/pod/Mojo::Transaction::WebSocket#json
So subscribing to a 'You should never see this.' event is weird ... probably won't work ... I think Mojo should reject this event, but it probably doesn't die because of something or other (register events something?)