Cut and copy in UR functions the same regardless of how many items are selected, and copying 1 item could not take longer than copying multiple. You can observe what is on the clipboard after cutting or copying from UR or another app using
https://freeclipboardviewer.com/
With that app running side-by-side with UR, I see the clipboard consistently and immediately being updated on cut or copy from the details of a text item, even when selecting and immediately copying or cutting.