It's really a trivial one but since I think that behaviour wasn't intentionnal I'll report it here.
User can push all that buttons and opened all the sub-window at the same time. It's pretty useless since he can't switch from a window to another one.
Side-effect : doing this will shadowing more by more the launcher background.
(here Build Type info + Build Version info)
(here Build Type info + Build Version info + Server Port info)
Strangely we can still press info button to open window but not press it again to close them, it may worth since it's a pretty intuitive behaviour for help bubbles-window (in other we just have to click aside to close the most foreheading window).