You can now hide Title Bar with vertical tabs in Microsoft Edge. The appropriate option is available in build 91.0.825.0 of the browser. So now you can shrink the title bar height when you have vertical tabs enabled in Edge.
Microsoft has released a fresh update for the Edge browser in the Canary channel. The biggest visible change in this release is the ability to resize the vertical tabs pane. In its current form available in Stable, Beta, and Canary channels, the sidebar has a fixed width, making it a bit harder to read long tab headers. Now, you can resize this bar according to your needs. This change is especially welcomed on computers with ultra-wide monitors with tons of free horizontal space. It is also worth mentioning that you can change the panel's width whether it is pinned or not.
Microsoft has made the Vertical Tabs feature available to Dev and Canary channel users of Microsoft Edge. Earlier available as an experimental feature, it is now accessible to everyone.
Microsoft is testing various layouts for the Microsoft Edge's Vertical Tab option. Currently, the browser shows a button prior to the tab row on the left. By clicking on that button the user can move the open tabs to the left and stack them vertically, or restore the traditional horizontal tab layout.
How to Add or Remove Vertical Tabs Button on Toolbar in Microsoft Edge
Recently, Microsoft has added the vertical tabs option to the Edge browser. It is an alternative layout of the tab row, where the tabs are arranged vertically. There is also an option to collapse the tab bar, so tabs turn into website icons. For users who prefer the classic horizontal tab row, Microsoft has added the option to remove the vertical tabs button to save the space.