Regarding Kicad Symbols and BOM

Hello there!

Thanks for reaching out.

This information should be already available on the Library Symbol Properties.

For instance, check the LM358N/NOPB part here:
https://www.snapeda.com/parts/LM358N/NOPB/Texas%20Instruments/view-part

You'll see that information such as Manufacturer, Availability and Distributors links are available.

That being said, please let us know if you're looking at a part which doesn't have any information available so our team takes a look.

Thanks!