Current XS

It has either border-radius = 0 for many elements or has a pretty small border-radius ( 0-3px). These two types of edges co-exist in the current XS.

Updated XS

Change made: Most elements to have round edges appropriate to their size. 

Motivation:

Apart from the fact that rounder edges look more modern and make the UI friendlier, round edges are easier to comprehend for the human eye.

Our eyes scan easier pages with round edges on elements. Source: link.

We should increase the radius to about 9px.