Currently, with the present compact option in Orion, just shaving off a few vertical pixels in tab bar height will probably satisfy these set of users.
We tried reducing the height of tab bar but decided that the few pixels were not worth the cramped look. Do you feel strongly about those few pixels?
Separate issue: with the Version 0.99.109-beta, it seems Orion always shows the tab bar even when only one tab is open.
Yep, will be fixed.
There is another set of users who would prefer "Safari 15-style" compact mode - that is where the address bar and tab bar is clubbed together.
We will make this an option.
Separate from this is the coloured tab option. Again, I am not a fan of this as I prefer my browser chrome and content to be separate. For immersive mode, I would look to go full screen or focus mode.
This is my preference too, but I understand that are other users who prefer colored chrome.