Focus Mask and even Live View won't make the laser redundant. As good as the mask is, there is the point of critical focus and the rest is depth of field and circle of confusion toleration.
So if the subject is at nine feet, ten and three quarter inches, the laser will tell you this. Even at its most restricted setting the focus mask will show subjects at, say 8 feet, and 11 feet as also being in focus (I'm making these numbers up to make a point. Don't take them as exact).
So, Live View will be good for accurate framing, and focus mask wil confirm focus, but for the critical focus that MF digital requires a Leica Disto 5 and fine focus marks on the lens (such as those on the Alpa rings HPF rings) will still be the preferable way of working.
I was dubious about this method, but after the first time out with it I found it to be fast, simple, and deadly accurate.