A solution is to go to your aircraft manufacturer and ask for a document, we call it a Technical Operational Response, stating they have No Technical Objection to the operation with the 2.1% slope. Then take that to the Airworthiness Authority seeking their agreement. Or seek a Flight Manual appendix from the manufacturer. The manufacturer's consideration would be tailstrike on the landing flare or on take-off rotation, which you would hope would not present a problem comparing 2.1% to 2.0% .