Which is why kicad had this hidden power pins hack.
While i agree that the symbol is rather large i think the best option to get them smaller is the one shown for TL072 But well it kind of violates KLC which requires a rectangle to be placed (could be amended with an exception for power units but that is something for @chschlue to decide)
The left small experiment is in violation as well as KLC requires power pins on top and bottom not on the side.
The other small one could be an option but i am not sure i like it.