Hardcoded slippage tolerance risks poor trading or DOS

Impact: Medium

Likelihood: Medium

In the PositionInteractionFacet.sol contract, the slippage tolerance is hardcoded to 2% in the _applySlippage function:

function _applySlippage(uint256 amountIn) internal pure returns (uint256) {
    // 2% slippage from quoter estimation
    return amountIn + (amountIn * 20_000) / DEX_PRECISION;
}

This implementation presents several critical issues:

1. The fixed 2% slippage tolerance doesn't account for varying market conditions and liquidity pool depths.
2. During periods of high market volatility, this fixed tolerance may be insufficient, leading to failed transactions (DOS).
3. For highly liquid pools, 2% slippage is unnecessarily high, resulting in worse execution prices for users.
4. For low liquidity pools, 2% might be too low, causing transactions to fail when they could have succeeded with a higher tolerance.

Allow the tolerance to be set by the admin/owner.

Published by Pashov Audit Group, with Carlos (Bloqarl) participating as a contractor. The source report states that its fixes review was not fully completed; no final remediation disposition is recorded for this finding. Read the full report.