I think the difficulty is that F12 means, "launch the preview." It has no clue where you were when you minimized it. F12 does not mean, "restore a minimized window." I have to wonder whether the OS would even let an app do that.
In my opinion, as a former developer, the operating system has nothing to do with restoring a minimized window, especially in Java applications. The code to close a window or to minimize it is not the same. Moreover, re-creating a previously closed window is much more expensive (in terms of CPU and memory) than restoring an iconified window. In the latter case, the application usually still has the previous state in memory. It is this last point which motivates my request.
Easily worked around - if you've just minimized the window (rather than closing it), noodled with settings, then want the window back, just maximize it again. Mouse-hover on the icon in the taskbar, and click on the preview window.
True, but it is often faster to press a key
