The Look In Override option just has it parse 2DAs in the Override whenever a 2DA is used in a template like a UTI, UTC, etc. It won't show up in the main asset browser. You'll have to open it manually via the 2DA editor (1st button under the top menu row).
But KTool is old and creaky and not recommended to be used any more. There are multiple alternatives these days, including a new 2DA editor that was literally just released in the last 24 hours.