Do I need the washer that goes between the blades and the spindle?

I have a Gravely Pro-Master 148z and I've been doing some research on best setup. I was watching a video where a guy said on his zero turn he can lower the blades on the deck in the fall for leaves and then remove the spacer for the spring and summer time. I've been doing research on making the mower stripe better and high lift blades were recommended and I think if I remove that small washer between the blades and the spindle it'll give more deck to brush the grass blades over too. Just wondering if anyone knows if it's important for that spacer/washer to be there.

Thank you!