Do you want a small taskbar, or, perhaps, to put it atop?

Windows 11 doesn't want you to have that, so here are some registry tweaks to help you out. This might differ in actual RTM Windows 11, this one seems underdeveloped. This video might not survive a test of time, since it is an early leak of Windows 11 SE.

Nonetheless, rest assured - registry can do anything and beyond, even if the final product will be as poorly executed as this beta. Fingers crossed.