See wf-recorder and wlrobs.
Automatically maximizing windows
You can maximize specific windows by default with the following command:
~/.config/wayfire.ini
[window-rules]
alacritty = on created if app_id is "Alacritty" then maximize
You can get the properties of your applications with the following command:
WAYLAND_DEBUG=1 alacritty 2>&1 | kak
See Window rules for more information.