Show custom code (option at the bottom left) in a large pop-up window to be able to better customize code directly in it.

The field is only a small one-liner!

You have to copy the code back and forth again and again (even if I only want to adjust a small parameter), because you have no overview at all in the small section.

Instead of the small text field, simply add an "Add Code" button, which then opens a popup or modal with a large text field / editor field in which you can then work with the code properly.

And activate (flashing cursor) the large field immediately after clicking on the button, so that you can copy in the code directly after clicking on the button (without having to click in the field extra).

I think this is just a small effort that makes it much more convenient for some code-savvy users...