Aztec wrote:Btw, still regarding tabs, did you look at opera 12's source code to see how all of this is done? Maybe you wont have to rewrite the extension just for this.

Considering that Opera/Presto's code is C++ while Ambassador uses XUL, XPCOM, HTML, JavaScript, and CSS, the code is just not that comparable. It would be a ton of work (months, if I had to guess) just to figure out what the C++ code does and then essentially rewrite all of that with the aforementioned technologies. I'm also not sure how legal it would be to utilize, in any fashion, source code that was neither intentionally published by Opera nor licensed under an open license.
It would really be easier to implement a brand new extension for Pale Moon or Basilisk that implements a similar set of features as to what you are looking for, and I encourage your or anyone who wants to try their hand at making one to do so. At this time I simply do not have the time to completely devote myself to a project of that size, and from a directional standpoint, I intend for Ambassador's look and feel to stay more or less as it is.
One last tip - if you want to run Ambassador in a single browser tab, while not technically supported and not totally bug-free, you can try it anyway. It's basically like running the whole window in one tab. Simply put "chrome://ambassador/content/" into your address bar. See also
this part of the ChatZilla FAQ (which is mostly applicable to Ambassador).
a.k.a. Ascrod
Linux Mint 19.3 Cinnamon (64-bit), Debian Bullseye (64-bit), Windows 7 (64-bit)
"As long as there is someone who will appreciate the work involved in the creation, the effort is time well spent." ~ Tetsuzou Kamadani, Cave Story