Paradoxically, the chances of it working are determined by whether it's a very good suit or not-- cheaper is better. Fused suits seem to adapt to changes in the lapel roll better, since there usually isn't much in the way of underlying construction defining the roll. A proper canvassed suit will have a number of elements that predetermine where the lapel will roll, and changing it would require disassembling the chestpiece. I have had good luck converting a fused 6 on 2 (low button buttoning) double-breasted suit to 6 on 4 (middle button buttoning). The first time I button it in the morning I need to roll the lapel properly, then it seems to take the set. One other thing you might consider that could help: a row of stitching behind the lapel defining the desired roll may help the jacket "adjust" to its new roll, especially if the stitching is done such that it generates a little tension between the outer fabric and the inner layer. This is not something that anyone can do, however. You need an experienced tailor who understands the objective. And it will have to be deftly done handstitching.