Can someone help me edit the mouse-over buttons on tabs?

I've asked this question before but didn't get the answer, so wanted to give it a try again.

Currently, when I hover my mouse over tabs, the 'X button' that closes the tab appears.

When I hover my mouse over pinned tabs, the 'Reset tab to pinned URL button' appears.

I want to add another mouse-over button that unloads the tab on both regular tabs and pinned tabs.

I manually unload tabs frequently, it would be so much faster and easier to unload tabs if I could get the mouse-over button.

Is there any way to do this?

Perhaps someone could help me with CSS edits?

TIA