I have picked up MasterPlan as of today as a less heavy version of Miroboard which it works quite nicely.
My only suggestion being: Allow text be copied and pasted in and out of MasterPlan.
Haven't found this mentioned anywhere else or if clipboard is meant to be working with MasterPlan (I have been using it on Ubuntu).
Edit: I noticed finally there is paste content option in the menu but it fails to paste plain text into a task, doesn't appear in the log or running the software from the terminal the exact reason for this failure. Never the less, being able use clipboard keyboard shortcuts would be the best solution for this.