I just recently moved back into using Firefox since I decided to go back to Kubuntu (Linux distro) because win10 will soon become unsupported. I like using vertical tabs to get more horizontal space for the webpages I visit. I like how Firefox designed their vertical tabs but I do not like how the bookmarks overlap the left most side of the vertical tabs. I like having the bookmarks bar on new tabs but not on tabs that have open webpages on them. In Edge, this does not happen. The upper part of the vertical tab is always the same size whether or not bookmarks is showing or not. I hope they get this sorted out so the tabs won't be moving every time we open a new tab and the bookmark bar shows up. I have attached a file to demonstrate what I am talking about.
