More visible relation arrows across lines (Frontend)

**Is your feature request related to a problem? Please describe.**
I have been working on a dependency parsing-like project.
Each node is a single line, and I want to draw a tree over them.
However, it is really hard to distinguish between arrows and to identify both ends.
Please check the screenshot below. (I cannot disclose the whole content because it's private, but each line is a sentence.)

**Describe the solution you'd like**
I wish the left span of the annotation page dynamically expands and the widths of the arrows dynamically adjust, so that it can accommodate arrows and labels so that they do not awkwardly overlap.

**Describe alternatives you've considered**
I considered concatenating some of the rows so the arrows depart/arrive in the middle of the line, but as data are segmented by newline removing some of them makes no sense.

**Additional context**
Screenshot: