I emailed support asking what happened to "my window" and here is there response:

"The "Refer Fields" option in the free flow mode has been deprecated. The names of the forms and the fields would be auto populated when you start typing the script in the free flow mode."

So I tried today to see what they meant by "auto populate when you start typing" and it is comparatively speaking a useless feature for developers to rely on.

"Refer Fields" offered complete access to every field name and field-type information across all the tables in the application while a developer is working on free-flow scripting mode, which made it an essential feature to refer to when writing, editing or troubleshooting deluge code between tables.

The new, "auto populate" feature, appears to only displays a short list of fields beginning with whatever string you begin to type, so you have no way to quickly correlate field names/types in other tables with the one you are working with. If that is the case, the new version makes it harder, not easier to write deluge scripts and therefore I would like to initiate a petition to get "Refer Fields" feature back if the other members of the community agree.