The automatic locker (Lockright, Detroit etc) does not keep the tires locked together on turns. It allows the outside tire to disengage so it can speed up as the ground drags it faster around the outside of the turn. To get it to lock up on a turn, you have to break traction on the inside tire so it can spin and catch the outside tire forcing it to lock back up. It's all about how you drive it.
On the front where the tires turn a lot, the speed differences are constantly varying and it is herky jerky as the locker is constantly unlocking and relocking a tire. This happens even in 2wd if the hubs are locked in. In 4wd on the snow and ice you have to be careful and sometimes it feels like there's a poltergeist in the steering box fighting you for control. But it's not bad if you take it easy and remember that either lifting your foot suddenly, or stepping on the gas suddenly is what is causing it. Drive smoothly both in turns and with the accelerator and it isn't a problem.