I use Qucsstudio4.2.2 (super good stuff!!) extensively to e.g. make matchings. Here I often need to tune a match so a power amplifier has a load that is optimal for its loadpull contours.
At the moment I do it like this: I just create a loadpull contour plot from my loadpull data with Python, and use this contour as a ‘picture’ in the schematic. With this picture as an overlay on top of the schematic’s Smithchart, it is possible to tune the match to the optimal spot in the contour. (screenshot of an example attached)
But it would be much more effective to be able to import the loadpull data as e.g. a generic MDIF or a .lp file.