How to disable window manager when maximised?

Hi im using zorin 16 core + WINE (zorin edition v5 from software app)

I installed a program (PDF-XChange editor) which has it's own custom top menu bar in windows.

When I maximise the window zorin window manager top bar appears on top of the programs menu bar.

how can i disable zorin top menu bar for some apps?

Mixed reviews and mixed results - but you might try them out:
https://extensions.gnome.org/extension/1287/unite/

https://extensions.gnome.org/extension/723/pixel-saver/

Thank you I tried UNITE but it didn't work for WINE app.
The Zorin top panel was still visibile.

In KDE Plasma (Kubuntu) the GUI has an option to "disable window border"
Which turns off the top panel styling and lets the native apps top panel override.
This can be set on a PER APP basis which is nice

This seems like a reasonable feature to implement on Zorin.
Is there any way to do this currently even by the shell commandline??

Not easily, no. The window border is part of what manages the Window. IT's position, it's resizing... You can reduce its size a lot, but cannot remove it entirely. It is part of the window manager. It includes the Close button for the window and... on Gnome apps, all other menu functions and buttons.
You could disable it in terminal, but would regret it when your windows lose functionality and you must reboot the computer to get it back.

Dam that's a shame. Really like Zorin much more than KDE Plasma.
The UI overall is much more polished/well finished.
Just lacks the customization of KDE.
Was hoping to find some way to manually achieve this.
Hopefully the developers see this & consider it as a feature addition

You can suggest this feedback in this Poll that the ZorinGroup may consider in future releases:

Some are curious as to how the Zorins may add their style to a KDE D.E.