Current ULS language list window has the following HTML:
<div class="row uls-language-block"> <ul class="three columns"> … </ul> <ul class="three columns"> … </ul> </div>
This HTML exists for appearance, to split the list into multiple columns. This is bad from accessibility standpoint and just unnecessary. Although that was an acceptable solution some time ago when ULS was developed, in 2021 there are more efficient and accessible ways of achieving that. I propose moving to column-width property for this (Caniuse query for it, supports IE11). If necessary (although I don’t see why the first list is split into two columns instead of 4), a column-count and width declarations can be added.
Example of ULS language list in new Vector (Firefox 88, Windows) with column-width: 12em applied (and HTML structure amended):