I would not have gone for a pure wingmast but a more rounded profile. With a wingmast it is critical to get the AoA (angle of attack) adjustment 100% while a rounded profile is more forgiving. But getting the bending properties right would be more important to me than the profile of the mast.
Tapering.. If you want to do it, do it. Just make sure you get the bending properties right up there. Kind of a black art I think as there is so little documented on the topic, but fast if done right. Unless you are pretty certain you get it right, it is probably more work than it is worth.