Some templates adds a lot of nested boxes, as the result a lot of useful space is used for borders and spacing between them, I think it's incorrect approach, and we've already implemented some fixes and update will be in 9.1

Actually the initial template for UNA had no borders at all in the past and site space was user very effectively especially on mobile, since we tested on mobile first. But after the time more, more and more borders were added for various reasons. 

As a temporary fix I would suggest to remove box and leave it as content only for timeline block in pages builder.