We aren’t going to add a blend between single target and multi target. The reason for this is because, in our opinion, it just doesn’t work.
Our strategy is to instead model different types of fights and then you can pick the fight type you care about most. In BfA we are going to focus more on making multiple boss scripts for each tier of content. We will also update the addon to support multiple sets of gear. So then you can just press a button to swap in the gear for the fight you are going to do, which will work much better than trying to “blend”.
The problem with blending two different sets of simulation results is that you invalidate the data from both sets. The tank blender works because it is all data from the same set of simulations.