Didn’t Bluefin originally have a custom GNOME layout based on Unity, where the main bar was on the left and also had a top bar? What happened to it? I assume it’s not maintained anymore, unless I’m remembering wrong. I like that layout better.
I like this layout e.g. when Text Editor is launched.
Yes, Text Editor occupies whole screen. When I want to get application menus I simply press Super key and “normal” application plus top bar is displayed. This is just do not disturb me mode and allow me to focus on my current application.
For this purpose I use “Hide Top Bar” extension with setting like this:
EDIT:
If you use @j0rge suggestion with combination “Hide Top Bar”, then I suggest to uncheck bottom Jorge’s setting.