If there's only one option in the Stock table, the Unit Selector still appears in the Product List and Product Page as a dropdown, even though there's only one option.
See in the video:
https://www.screencast.com/t/erjcy8WYY
I think this is bad UI, as the user thinks there's more options only to find the only option is the one that is already selected.
My suggestion is to make the dropdown readonly when there's only one option, so it doesn't confuse/mislead users into thinking they have more options and wasting opening the dropdown.
Regards