This was my mistake. I forgot that I was also using SetLayeredWindowAttributes for transparency. After I removed that, a single Call is all that was necessary:
SetWindowPos Me.hWnd, HWND_TOPMOST, 0, 0, 0, 0, SWP_NOACTIVATE Or SWP_SHOWWINDOW Or SWP_NOMOVE Or SWP_NOSIZE
working fine now.