Start11 v2 2.0.0.4, with Windows 11 build 22621.2428 (22H2) and build 22631.2506 (23H2).
1. When Taskbar auto-hide is enabled it has a large gap where the Taskbar used to be at the bottom of any maximised window:

This does not happen when using Windows auto-hide. The main reason i use auto-hide is to get some extra vertical space, so right now the Start11 auto-hide is a bit pointless. But apart from that i like how the Taskbar appears/disappears quicker and i also prefer the fade in/out animation over the clunky old Windows auto-hide animation.
2. Occasionally with auto-hide, when the Taskbar fades in, it will be empty. All of the pinned Taskbar apps will take 1 - 2 seconds before they appear. This is random and i can't find a reliable way to replicate it, but it
maybe happens more often when the Taskbar has been hidden for at least a few minutes.
3. Another auto-hide problem - Sometimes when a window/app is open it wont appear on the Taskbar until i click on the Taskbar or open another window. Below you can see how the Settings app is not appearing (it should be right under the red arrow):

4. If you open File Explorer and then click on the file icon in the Taskbar with the middle mouse button, it will open a separate File Explorer window. This no longer works when using the Enhanced Taskbar.
Thanks for the bug report.
We have addressed the first issue for the next update as that was a bug with not setting things initially correctly.
The repainting issues have been tweaked too.
With regards to the middle click, that is working correctly here. The only time it will fail I think is when explorer already has a This pc window open. It will then not open a new one as it already has one.