Some time ago MobileFrontend [beta] acquired a nice blue button that goes to the
top of the screen.
In RTL wikis the upward-pointing arrow in this button is misaligned.
Some hints:
It should be enough to add a change to the LESS file of the back to top feature, which distinguish the left/right 50% value using the rtl and ltr class, which is added to the html tag :)