Slic3r Prusa Edition in the latest version 1.36.2 comes with improved printing with water soluble supports. On Prusa i3 MK2 MultiMaterial you now have three ways to print with support. Basic supports from the same material as on regular MK2/MK2S, water soluble supports everywhere and water soluble only on the interface layers.
Here is the video presentation:
With this features, Prusa is getting more powerful and competitive even when compared with much more expensive machines.
Prusa post with detailed information: