https://superhivemarket.com/products/qol-tools--snap-off-copy

 Do you ever find yourself just wanting to copy "that selection" for a new object?   Snap off copy is a very simple little addon that does just that.    To be clear, it doesn't do anything you can't already do in Blender - it just takes a bunch of steps out of the process.  For me at least: Quality of Life in Blender just just gets that little bit better.

What does it do?

In edit mode, Snap off Copy allows you to easily duplicate any components (face, vertex, edges) into a fresh new object.

Quick, and easy.

When you're working on a mesh and already have a specific shape you already want to use, simply select Snap Off Copy from the right menu (or HUB Pie) and you're done!