Using Brave 0.18.14 on newest Macbook with MacOS 10.12.5. Doing ANY editing of bookmarks has a VERY slow keyboard response - like 5-10 seconds before keystrokes or mouse click echos on the screen. Also when changing folders in Bookmark edit window it takes 20-30 sec for the selected folder to show and sometimes it simply forgets the folder choice and the new bookmark shows on the Bookmark menu line. Clicking Done button also pauses for quite a while before closing the window.
Another quirk is that sometimes when you create a new sub-folder using the Bookmark Edit window, it creates multiple new folders with the same name - sometimes 5 or more.
Seems to get worse the longer the browser is open (loaded in memory) suggesting a memory leak, but this might be subjective of me.