JDK & FX SDK cobundle silent mode installation process can't be finished without user interactions. JDK installs silently, then FX SDK pops up(FX SDK does not support silent installation) and installation process waits until FX SDK installation is completed.
If someone uses /qn /s(qn - No UI) options it is supposed that process will be finished without user's interactions.
The silent mode option should not be supported or should be finished after JDK installation is completed.
Did not find any related information in JDK & FX SDK cobundle ReadMe.