// First conversion correctly uses actual received amount
gotAmount, transferResp, err := p.evmKeeper.ERC20().Transfer(erc20, caller, transferTo, amount, ctx)
if err != nil {
    return nil, fmt.Errorf("error in ERC20.transfer from caller to EVM account: %w", err)
}
coinToSend := sdk.NewCoin(funtoken.BankDenom, math.NewIntFromBigInt(gotAmount))
actualSentAmount, _, err := k.ERC20().Transfer(
    erc20Addr,
    evm.EVM_MODULE_ADDRESS,
    recipient,
    coin.Amount.BigInt(),
    ctx,
)
if err != nil {
    return nil, errors.Wrap(err, "failed to transfer ERC-20 tokens")
}

// Only burns the amount after fees, even though fees were already accounted for
burnCoin := sdk.NewCoin(coin.Denom, sdk.NewIntFromBigInt(actualSentAmount))
err = k.Bank.BurnCoins(ctx, evm.ModuleName, sdk.NewCoins(burnCoin))
// to preserve an invariant on the sum of the FunToken's bank and ERC20 supply, 
// we burn the coins here in the BC  ERC20 conversion.
// In msg_server.go convertCoinToEvmBornERC20:
actualSentAmount, _, err := k.ERC20().Transfer(
    erc20Addr,
    evm.EVM_MODULE_ADDRESS,
    recipient,
    coin.Amount.BigInt(),
    ctx,
)
if err != nil {
    return nil, errors.Wrap(err, "failed to transfer ERC-20 tokens")
}

// Burn the full input amount, not the amount after fees
err = k.Bank.BurnCoins(ctx, evm.ModuleName, sdk.NewCoins(coin))
