Hi,
Because there are many more options within the Pro version, the image options are moved under the General Options panel as a sub-menu element, here: https://i.imgur.com/11yeoE5.png
The two plugins are indeed separate, so that you can switch back to the lite version anytime, without changing/overriding the options. We are working on a solution to import the configuration from the Lite version to the Pro version, but it may take some time, as there are many different versions of the Lite version in use via the wordpress.org network. I understand it can be frustrating, we are working on a solution for that.