Known limitations

Displays and Spaces

One display. Layout manages a single display. It won’t activate with a second display connected, and it pauses if you connect one while it’s active.
macOS Spaces and full screen aren’t workspaces. Layout’s workspaces don’t use macOS Spaces: Layout moves windows in and out of sight instead. A window in macOS full screen is left alone, and Layout refuses to switch workspaces while a window it would hide is in full screen. Leave full screen before switching.

Dialogs and other non-standard windows, such as modal windows and panels, are left out. They stay where their app puts them.
Windows of apps that refuse to move can’t be sent out of sight or placed. Some apps also refuse to be moved off screen.

Minimum sizes. Some apps impose a minimum size, and some, like Simulator, can’t be resized. Their windows can overflow their zone. See Layouts and zones.
New windows. Whether an app creates a window depends on the app. Launching an app that’s already open but has no window doesn’t guarantee that it creates one. Layout shows an error when that happens.
Where web pages open. Apart from Firefox, each browser decides which window and tab your pages open in.
Staying on top. macOS keeps the focused window in front. Layout can’t pin a window above the others.

Dragging apps between zones in the editor. To move an app to another zone, remove it from one zone and add it to the other.
Changing the order of the apps in a stack.
A shortcut to cycle through the apps of a stack. Meanwhile, use ⌘Tab with the replacement on, or the Layout bar.
Undoing changes you make to a layout in the editor. ⌃⌥Z undoes window moves and resizes only.
Rules based on a window’s title or document.
Splitting a saved desktop. A saved desktop keeps a fixed frame for each window; choose a template to turn it into a regular layout.

Which window belongs to which workspace. Layout saves your workspaces and layouts, but not the windows in them. After Layout restarts, every open window starts in Général. See Workspaces.
Undo history and link memory. The undo history of window moves and the memory of which app links are already open are kept in memory, and cleared when you pause or quit.