But there is a detailed section on the SAR for explanations. If it says "This guy keeps bringing in coins, he says he buys them from the Mint", it is going to get a big yawn from the authorities since they will have read a ton of SARs that say the same thing. If it says "Our customer keeps saying that all of his clients pay him in dollar coins" that may bring further attention if the IRS is flipping through the SARs and can't fing a business associated with that bank customer.
I made my first deposit using the coin machine ($1,000) today. I wish I had done that before. Very convenient. I use 5 banks and a couple give me a bit of attitude. The coin machine gave me no attitude.