Pasting in linked columns

I’m not sure if this is me not getting how to do something or if this is a feature request.

I have a select list column with a thisrow filter applied to it that makes it lookup into another table. I am able to type new data into a cell and have it be created in my linked table just fine by clicking the + sign when it appears. But if I paste into the same cell, the pasted data doesn’t create a new entry in my linked table and the + sign doesn’t show up. The new data appears in the table where I pasted it, but not in my linked table.