Make close tab button less prone to misclicks

In the current desktop user interface (Opera 44, but likely since version 15) each tab's Close tab button remains invisible on its left side, hidden under the icon until the mouse moves over the tab (except for pinned tabs or when many tabs are open, in which case there is no close button). I often find myself closing a tab which I meant to select, a nuisance that I don't experience so often in similar interfaces. Given that my behaviour doesn't seem to improve, any change on the user interface, whether by default or optional, would be welcome. Others have expressed concerns about this in the forums,[1][2] but I don't know the site's rules regarding resurrecting posts and I believe that I am not simply repeating their words in spite of sharing the sentiment.

The following are some changes that users such as I might benefit from:

1. Make the button square and/or require the cursor to be close to the center of the button. This might not be a great solution but it might help: there are times when the button becomes active yet the cursor's tip seems outside, so in spite of the visual rendering it looks like clicking will not activate the button (it might be a display issue on macOS or a wrong appreciation due to poor eyesight; whatever the case I believe that a fix is warranted).

2. Move the button to a position less likely to be clicked on by accident. I am not sure whether I really tend to target the icon when moving the mouse towards the tab or not, so this might not be of any help.

3. Make the button always visible. Doing away with the tab's icon or moving it might work but is perhaps not desirable. Since transparency is unlikely to work, this option might also require moving the button.

4. Enable the close button only on the active tab. Users who close many inactive tabs by clicking on the button will be hindered by this, though for fast double clickers it might not be a great pain (specially if the double click is implemented as such and doesn't require bringing the tab to the foreground).

5. Enforce a delay between mouseover and button activation. This might slow down closing a sequence of tabs by using the button, though workarounds might be possible (for example immediate activation either on double click or when the close button appears under the mouse cursor because a tab is replacing another one that has just been closed).

6. Get rid of the button. A bad behaviour by default since the use of the middle mouse button for closing a tab might not be known or available to many.

Hoping that some of the points above might be be taken into consideration, I thank you for your patience in reading through this. Cheers.

Enable the close button only on the active tab. Users who close many inactive tabs by clicking on the button will be hindered by this, though for fast double clickers it might not be a great pain (specially if the double click is implemented as such and doesn't require bringing the tab to the foreground).

I have just realised that this is the behaviour when there the tab width is small (normally due to many open tabs on the window), just the case where ‘power clicking’ to close tabs might be most important. It would seem reasonable to extend this behaviour to tabs of any width as a solution to the issue described above.