If you want to make sure there aren't two entries with the same 'single select' selected, it would be great to have an option in the settings to "only select unused' selections so that when one selection was used, it will not show up as an option for subsequent records.
Use Case: Interior Design. You have a single select filed with all the rooms you are designing but you don't want to accidentally have two entries for "dining room" by mistake.
Any scenario where you want to make sure you only have one entry per single select option can use this setting.
Thanks!