Made My Own Arduino Board - ATMEGA32U4 - Bootloader Questions

I am looking for someone who REALLY knows the answer. Please do not reply if you don't know or may have an idea. There has to be somebody who has put the bootloader on the Leonardo Board.

Is the 'Catarina-Leonoard.hex' in the Arduino folder the legit arduino bootloader?

Why is this file 78KB if a bootloader is only ~4KB?

Thanks for the support,
-Peter