I would advise against hewing one face , then walking away from your log for any extended period, (even hours) wood reacts to milling even in log form in that you are relieving and creating stresses as you remove material. These internal forces are amazingly powerful and hewing is the best window I know of though which to gain an understanding of how to anticipate how working a piece of wood effects it's "balance" for lack of a better word. To some extent you can accentuate or minimize curve by delaying action.

This doesn't mean to hew is to race it just means it's best to always at least score the side oppisite from the one completed.