Today I worked on preparing myself to begin the project.
I first update all my published Unity assets. I had to do this maintenance for some time, and doing it now allows me to clear that from my TODO list.
I also create a public Trello board to track the work to accomplish. I started filling it, and you can read it here: https://trello.com/b/NMAp7Sl6/the-panel-dc-remaster
I also finally select that this game remastering will be on the latest Unity LTS version (2019.4). Then it should keep the initial game compatibilities.