Yes, I have, the largest being 12" x 20" x 20', and these were in fact heart centered, there were shipped off the day I sawed them, so as to how they behaved,?? no clue, never heard anything either way. My max length was basically 20', a typical LT-40 frame. Most beams that were just beams, I've always tried to saw heart centered, with only a few that folks either read something or knew something I did not in regards to FOH beams, of these I've sawn, they did favor the tendency to bow, and at times twist. The real challenge in my limited, (I need to stress) experience in beam and cabin sawing, for folks, all of which only a few I did not know from Adam, had a material list and an "X" amount of logs to work with. So, getting the most, usable parts was the goal. Most of the time I just sawed what size was asked for, whether it was engineered or designed, I have no clue except for a few. And they were not the big monsters, like 12" x 15". The big ones I sawed back in 08' I have no idea what they were for, when I asked, the foreman of the yard just shrugged his shoulders, with that look, "who cares?" so that was that. To reduce the amount of bow on the FOH D-logs, whatever the finish dimension was, when I took out the beam, I would make it heavy, by at least an inch, then bark side down, flat on the rails, and bring to size. From here, proper stacking is required, just like lumber. And just like lumber, there are no guarantee's to the final behavior, beams are tougher I think in that for the most part, once of the mill, whatever form they take, its pretty hard to fix.