So they finally gave up: "You want to demo our OS ? Just buy few apps from our store!"
So I updated to the latest build, it created 450MiB recovery partition with "diag" flag. I haven't seen this thing being advertised, at least it shrinked system partition without touching OP space. And it completly broke my GRUB. Way to go Microsoft ;) Most funny thing is that I had to give Windows partition "boot" flag to even update.
They fixed notifications showing that I have pendrive mounted, which haven't been plugged for few weeks.