I entered the latest RD TABS version into "full screen" (no menus etc) mode but I can't seem to exit the mode (what is the hot key to toggle?).
When I exit and come back in RD Tabs remembers the mode. 😣

The only thing available is the PLUS button to add a tab and my current open tabs.

Float your mouse to the top of the screen and the menu should appear. If that doesn't work, float your mouse to the top of the screen and click (this is an alternate option in the settings). If that doesn't work, close RD Tabs and go into the user.config (under appdata, Avian_Waves, etc.) and edit the following section so that it says "FALSE"

<setting name="WindowFullScreen" serializeAs="String">
<value>False</value>
</setting>

Tha did the trick with the config file.