getDepositFeeInBNB() assumes a stablecoin price of 1 USD, which may not be true if it depegs

Description

In Batch.sol, function getDepositFeeInBNB() calculates the fee amount in BNB, considering that the stablecoin price is 1 USD, which may not be true, as we've seen with USDC in the past.

It also means that if a coin other than a stablecoin is used to deposit, a much smaller/larger fee would be triggered. For example, 20 tokens are deposited, the fee is 10%, so 2 fee amount. The token price is 10 USD. The bnb price is 250 USD. The fee amount in BNB would be 2/250 = 0.008.

So the user would deposit 20 tokens, worth 200 USD and pay a fee of 0.008 BNB or 2 USD, which is 2/200 = 1%, instead of 10%. The real fee, according to the code, is depositFee/(token price in USD).

Recommendation

Consider fetching the price of BNB in units of the to be deposited token. This way, the fee in the code will match the real percentage in USD.

Status

Acknowledged