I have tried Qt 5.6.0 Alpha to see if I could manage to successfully create a static linked plugin. I was having a problem similar to QTBUG-35754 (QtQuick and QtQuick.Controls modules are not available at runtime static).

It happens that the problem seems partially fixed. It doesn't complain about:

module "QtQuick" is not installed
module "QtQuick.Controls" is not installed

but it complains about being unable to find qml files that belongs to those plugins such as ButtonStyle, StackViewSlideDelegate.qml and so on.

I'm initialising the plugins with the following code:

qobject_cast<QQmlExtensionPlugin*>(qt_static_plugin_QtQuick2Plugin().instance())->registerTypes("QtQuick");
qobject_cast<QQmlExtensionPlugin*>(qt_static_plugin_QtQuick2WindowPlugin().instance())->registerTypes("QtQuick.Window");
qobject_cast<QQmlExtensionPlugin*>(qt_static_plugin_QtQuickControlsPlugin().instance())->registerTypes("QtQuick.Controls");
qobject_cast<QQmlExtensionPlugin*>(qt_static_plugin_QtQuickExtrasPlugin().instance())->registerTypes("QtQuick.Extras");
qobject_cast<QQmlExtensionPlugin*>(qt_static_plugin_QtQuickControlsPlugin().instance())->registerTypes("QtQuick.Controls.Styles");
qobject_cast<QQmlExtensionPlugin*>(qt_static_plugin_QtQuickControlsPlugin().instance())->registerTypes("QtQuick.Controls.Private");

Am I missing some initialisation or this is still a bug?