If I create a new TMS Ribbon application (from Delphi project new -> TMS Forms) and compile this project, the form can't be snapped to the left or the right of the screen.
"Snapping" to the top will maximize the window. That's OK. But this will only happen if you move the Form with "normal speed" to the top of the screen. If you are too fast, this will not work.
My testing suggests that neither of them is implementing this feature. I have "googled" extensively but I can't determine the correct location to hook into the windows messaging system to apply the required functionality. I think its something to do with hooking into the WM_NCHITTEST message but that's as far as I get. It is functionality that's available in a standard VCL app but it gets overridden by the Ribbons.