Vlad Well indeed, I'm not sure…? I'm using 0.99.109.1-beta and I'm not sure what you're referring to.
Looking in the Window menu I see no obvious way to know what peer tabs exist within a given open window, I just see the active tab title.
I know one can also cycle through tabs via Ctrl-Tab, per window.
…and "yes" as you say I can 'search' for a tab by entering a remembered fragment in the address bar of… any window I guess… it's open then to some interpretation what one should I expect to happen if when finding a match (in terms of what is an understandable interaction transition if I'm in window X and enter a URL that matches with a tab in window B. A more sophisticated user can guess, but I'm not sure it's the clearest interaciton… nonetheless, there are conventions to follow.
Finally, that feature assumes I recall enough about a given page, it's URL or title perhaps (extra points if it includes meta-data or even page content.) But what if I don't recall, that it's just 'that page I opened after that other one, that… I think is around here somewhere'.
The good old, basic "show users what's open" rule seems to apply here. When I don't have enough data/recollection for a search, then browsing is what we fall back on. In that case being able to see:
Window 1 - Tab A
…means that open pages are not invisible, and more importantly, are not findable.
Perhaps though, there's something I'm missing. 🤷🏻♂️ ☺️