Allow drag-to-side, but not drag-to-top in Ubuntu MATE (Marco)

I love the "tiling" feature in many window managers including Marco that means I can drag windows to the side of the screen and get them covering one half.

However, I never use the similar feature that allows dragging a window to the top, and it often triggers when I just want to move a window upwards.

Today I discovered that Marco (the non-fancy window manager in Ubuntu MATE and probably other places) does allow me to have one without the other, even though the UI configuration tools don't expose the option.

Here's what I did:

gsettings set org.mate.Marco.general allow-top-tiling false

Now my windows can be dragged to the side for half-screen maximisation, but not to the top for full-screen!