So I installed Sway and it’s working great. I would like Sway to be the default choice when I log in. I modified the /etc/lightdm/lightdm.conf and changed user-session=i3 to user-session=sway and also enabled sessions-directory=/usr/share/xsessions:/usr/share/wayland-sessions.
This made Sway the ‘default’ as in it reporting ‘default’ next to the name in the login menu but the pre-selected choice is still i3, which is not very defaulty.