Not sure i understand what you re asking but i would expect it to work in the assembly environment so that the tab slot feature can be added between two related parts.
Sheet metal tab and slot.
It also should work with sheet metal parts just like the sw video i linked to above.
You can also add edge types square fillet or chamfer to the tab.
Now if you want just the slot in the tab and slot property manager under tabs change height to blind and enter 0001 as the tab height value minimum.
I make a lot of weldments and sheet metal parts that are 12ga to 1 2in thk i use 1 32 per side for the slot.
As well as adding corner type sharp fillet chamfer or circular to the slot.
Tab and slot solidworks 2018 welcomed a great new feature called tab and slots designed for sheetmetal and weldments users.
Be mindfull if you have tabs on adjacent bends when the part is bent wrong it may or may not fit in all of the slots anymore.
Sheet metal tab and slot was introduced with solidworks 2018 and it gave engineers a great and fast way for a common time consuming task.
Default through all cut functionality for the slot.
But it did not last long or the first solidworks users started to demand more functionality like.