You are correct, I have not tested Nova in today's Nightly. I will never drive Nova until that border is dealt with. I'm following the relevant Bugzilla reports like a hawk, full-screen state is "fixed" but not any other window state yet.
Here's some context you should know. Roughly a year ago the ability to interact with top tabs in maximized and tiled windows under KDE Plasma was broken, and I stepped forward to ensure it was fixed. The left-hand behavior is correct, right-hand is where the break was.
The outer Nova border destroys this behavior and goes back to the right-hand example here. Even if the border is interactive, I would remove it in CSS as I value edge-to-edge tiled windows.
I've now tested the latest nightly, we still have no top/edge interactivity when the border is reduced in Compact Mode. This has been relayed to the relevant Bugzilla report.
Wrist strain occurs when required to precisely aim below the screen's top edge, in order to select a tab hundreds of times throughout a day.
Wow, it's so awful, I can't even describe!
Why would I need unclickable space around tabs and functional buttons?!! What genius invented that?!!
I use Firefox on Windows in maximized mode. Now I can't even click on tabs and minimize/maximize/close buttons at the edges of the screen! How convenient!
Why is everyone obsessed with super rounded corners? It's so ugly and inconvenient.
The last design with slightly rounded tabs was the best. I liked it as soon as it was introduced.
How can I return rectangular tabs?
Are there any plans to fix the excessive padding on window borders which causes unclickable elements?
Currently with the redesign, both on the normal and compact mode, because of these "floating" UI elements, things like window controls, tabs and scrollbars are not completely at the edge of the window. Because of this, when the window is maximized, you can't anymore just drag the mouse to the top right corner and click on window controls, to the right and drag the scrollbar, to the top and click on the tabs, to the top left and click on the pinned tabs or sidebar, etc. This is something that I think many users expect to work and also works fine on basically every other app, so I think it should be fixed, both on the compact and also on the normal mode (and the touch mode I guess).
This is also a problem when the window is not necessarily maximized but just tiled to the edge of the screen. For example, on Windows, if I drag the window for example to the right, it automatically tiles/snaps to the screen borders (and another window on the left if it exists). In this case, the borders should also be removed to make clicking on elements near edge possible.
Also, could the floating elements mode be decoupled from the density setting? For example, I would prefer the normal UI density, but without the floating elements. However, regardless of how it looks visually, I think the above problem should be fixed.
Other than that, I think it looks fine. One visual suggestion/complaint that I have is that the bar with the address bar and extension widgets always has a darker fixed-color, while the tabs bar has almost complete transparency. The cut between them looks too harsh, especially on more colorful themes with background images, like Alpenglow (and probably other themes with vivid background images). I'm not sure what the solution would be, but it would probably look better if both the tabs and the address bar had around the same transparency level and color.
For example, here, the cut from the Alpenglow background of the tabs bar to the solid background of the address bar is quite harsh, and the background again leaks below the bar through the gaps between elements. Similarly, even on the Default/Dark theme, there is quite abrupt transition to the address bar.
Although it looks previously looked similarily, I think it's now more noticable because of the gaps between elements. Also, in the old design, the background of the tabs bar was more visible and more saturated, so it matched the address bar color more nicely.
