This pre-release brings back floating windows on Windows OS; it seems the related GTK issues have been resolved.
On libmypaint, the smudge sampling now respects the pigment mode setting as well. Instead of additively averaging pixels within the smudge radius you can average subtractively, or blend the two methods. To improve performance only a small random selection of pixels will be sampled within the smudge radius, which doesn't seem to negatively affect the results.