Do I need to use the plastic collars on my shanks?

I'm setting up my keezer right now and I am installing my faucets on the collar of my freezer.

The shanks came with the black plastic collars that are supposed to go up against the wood. I think it looks better without them.

Is there any reason why I should use the black pastic collars on the shanks? The holes are a pretty tight fit, and the nut on the shank keeps them snug. Is there anything I'm missing?

I'd say you're probably fine. If the drilled hole is tight enough and won't pull through or put too much pressure on the tap connection, you're probably fine. The black collar just acts like a glorified washer and spreads the pressure over a larger area, but isn't totally necessary.

One option also is to get some Stainless collars to keep that consistent look going!