I've just uploaded a new beta version of FotoSketcher 3.50. You can download it here: https://www.fotosketcher.com/FotoSketcher_3.50_beta_2.0.exe
The new Painting 4 effect now supports manual brushes. The format for these brushes can be any transparent black & white .png file and for best results should be as rectangular and filled as possible.
Here is an example brush which can be used:
And here is an example made with the new effect (source photo taken yesterday in the French Alps):
The new algorithm is quite computer intensive and still requires some optimizing, so you will need to be patient to get good results :)