Yeah, when I'm in the snow, the front-engagement in Auto mode is anything but seemless. Naturally, it's going to quickly transfer torque until the rear slip is no more, then dial it back, only to have to push it forward again. Lock into 4x4, then it's smooth (slippery or deformable surfaces only, please).
And regarding locking the torque convertor, mine will only seem to do that in 4th or 6th. I have a Scangage on my truck, which I watch while towing our camper. I would love to lock into 5th gear, but as we all know, 4th gen OD button locks out 5th and 6th (grrrrrrr!). But even when I leave OD on, sometimes it will hold 5th gear if I'm holding steady on the throttle. But it's never locked the TC in that condition. Let off the gas a bit, and it may shift to 6th, then may lock TC. Or give it more gas, and it may shift to 4th, then may lock TC. But never 5th with locked TC. Again....grrrrrrr!