No.

Once for off, once for on. Twice for beeps, once for on. It's quite simple. A maajority of the NVDA users out there don't use beeps, so pressing twice for beeps would not rattle any new users out there. However, having to press once for off, then twice to turn it back on would certainly turn off new users to the screen reader, who may not know about add-ons and where to find them, or those who may not even be able to install add-ons in certain environments.

Again, look at screen curtain implementation to see what I mean.