If they extend his contract before his current deal voids, that void year cap hit will continue to be spread out at $2.2m/yr. That would give us $6.8m in space that can be used to sign him in 2025 that can’t be used for another player.
A one year deal with a $13m signing bonus and $2m salary would only cost the team $4.6m in 2025, which on net would create more cap space than letting him walk. Maybe replace some of that signing bonus with bigger NLTBE incentives to give us an even smaller cap hit while giving him a financial incentive to make more plays.