The pause after +++ was really sort of a hack to resolve race condition problems (entering command mode when the modem still had inbound data in buffer) rather

The pause after +++ was really sort of a hack to resolve race condition problems (entering command mode when the modem still had inbound data in buffer) rather than any kind of security measure, but it did have the upside of making it a little more difficult to get a modem to switch to command mode unintentionally. There were various other solutions to this problem but for the most part it didn't completely go away until the practice of moving data over the Hayes interface became uncommon.