I found the "Pack Window" shortcuts available in KDE and they work very well:
I would like to add shortcuts to move the window directly into the screen corners. Currently if I wanted to get my window into the bottom left corner I would have to do something like
Pack Window Left (Ctrl+Num4) +
Pack Window Down (Ctrl+Num2)
I would like to use a single shortcut, eg
Pack Window Bottom-Left (Ctrl+Num1) to move my windows in this manner - and critically without changing the window size.
As well I would like to be able to center my window with a shortcut, eg
Pack Window Center (Ctrl+Num5), again without changing the window size - though a second shortcut that centered the window and set it to a predefined size would be very nice as well, so that I could have something like
Pack Window Center - Large (Ctrl+Shift+Num5) for a 90% maximized window, centered.
I am currently using Manjaro KDE edition.