The plugin operates as expected.
The CoinPayments platform imposes a 0.5% deposit fee for all deposits. For more information see here: https://www.coinpayments.net/supported-coins
If you do not want to have any deposit fees, you must use your own full node wallets. However, there is no ERC-20 adapter available at this time, only forks of Bitcoin, Monero, and TurtleCoin can be connected as full node wallets to the plugin.
The MAX_CONFIRMS column is there for these other full node wallets. You can ignore it when you use CoinPayments. The CoinPayments platform makes its own decision on how many confirmations it requires before it considers a deposit confirmed. This information is also listed at the above link (Supported Coins).
P.S. I am transferring this discussion to the CoinPayments support forum, as this only relates to the CoinPayments adapter.