You would want to extract all of the contents of the downloaded taskbar_usertile_alpha_7_1_by_angelwzr-d3dcdoe.7z folder to another new folder. I used the free program 7-Zip to extract them. Next, you could move the folder to inside the C:\Program Files folder, and run the UserTile.exe file to have the user tile on the taskbar.
It appears that it may be a spacing size bug with that many notification icons in the system tray. As a test, set half of them to hide and not show to see if that may be it.
I worked it out without using this technique. Well I did, but I didn't read this.
I remembered when I last went to the startup folder in Windows 7.
I knew it was in user-homedir/AppData/Roaming/Microsoft/Windows/Startup. (Or something like that...)