Covering up the screen like you did is a good start, I would leave a little bit open on each end as well as the middle. Maybe one inch on each side. I make my own cages, so I don't have a link for you. Sorry.
I get plexiglass, mount it in an oak frame and clamp the frame to the aquarium. Then I drill holes in the plexiglass until airflow, temp an humidity are correct. This means lights cannot be placed directly on the lid, because they can overheat. I use UTH for heat. To keep the plants alive, I use an led bar inside the tank.
Still, you are asking the right questions and doing the right things. I am sure you will be an excellent BP keeper. Let us now how your next feeding goes and keep us posted on you progress.
David