I absolutely agree!!!
Here is another similar one: The left panel is hidden while the app is running - Usability regression? - #5 by stefano.menci
Anvil is great for beginners and allows to create an app from a little laptop screen.
But if you are a pro and you work with other professional IDEs and are used to having lots of windows readily accessible on your multiple large monitors, and then you switch to Anvil, where by design you can only have a very small number of windows available, all you can think is either this is not a tool designed for professionals or this is a tool badly designed.
I understand giving me the option of hiding some panels, I don’t understand the decision of forcing me to hide those panels. It hurts a workflow that would otherwise be smoother and more productive.