Hi. I’ve been experimenting with MrOtherGuy’s vertical tabs script. I found that the tab bar could be moved to the right side of the window with just two simple changes:

change line 19 from: margin-left: var(--uc-vertical-tabs-width); to margin-right: var(--uc-vertical-tabs-width);
and

change line 31 from: left: 0; to right: 0;
Works for me.