The Sections column on the left of the Notation Guide changes width when you select different sections.
e.g if I have Links selected, the menu looks like

ALL
Text
Formatting
Headings
Text Breaks
Links
Lists
Images
Attachments
Tables
Advanced
Formatting
Misc

If I have Text Formatting selected, it looks like:

ALL
Text Formatting
Headings
Text Breaks
Links
Lists
Images
Attachments
Tables
Advanced
Formatting
Misc

The fact that "Text Formatting" gets split over 2 lines makes everything else move down, meaning that it is difficult to navigate quickly through the sections (e.g. if you don't know exactly where the thing you are looking for is located).

This isn't a major problem but would be very easy to fix. I have only marked the versions that I have tested it on (mine is 3.4.2, yours is 3.4.3E).