List of thing you need for S+ on professional:

Gas Mask or Wolf Tail

-Gas mask:Gives you aim assist
You can get Gas Mask for completing game on professional

-Wolf Tail:Increases the power of melee attacks
You can get Wolf Tail for completing game on assisted under 4hours

-Armor Ashley:Makes Ashley invulnerable for enemy attacks
You can get Armor for completing game on hardcore with A rank

After you complete game on professional with S+ you will get Cat Ears that gives you infinite ammo

There are a lot of shortcuts in the game, but I won't discuss them, but I will post a link to the video
check it out! https://youtu.be/O4QIVealcHs?si=toLrSna6aQnk508z