Usually it only "locks" for one exposure so even if you decided not to take that one and didn't know how to unlock it you'd only lose one frame. On my XR-7 it's a handily positioned button on the upper left side near the lens mount. Push once to lock, again to unlock. Many cameras use a partial press of the shutter release. Press down half way and the indicator blinks to indicate lock, recompose and press the rest of the way to take the shot, or release to unlock. My 645 Pro AE Prism finder uses this method. It works well most of the time and is intuitive, but I prefer the separate button. Every now and then I push too far in trying to use the lock and shoot an ill-composed but well metered frame.

Seems a shame to me to have a 1V and only use it on manual. Don't get me wrong, I love manual cameras. I have an MX, a K1000, and Yashicamat 124 and a 4x5 field camera. But if I never wanted to use automation I'd just stick to all manual cameras and save the weight, complexity and need for batteries.