I believe this proposal could have a far more interesting dynamic with a vesting mechanism.
I.e. The lock-up mechanism begins with an 90% fee for vesting SDL early which will decay linearly. If tokens are vested early, the percentage of tokens that are still applicable to the fee will be sent back to a treasury. After one year, the fee would reach 0% and no tokens would be burned when vesting SDL.
This mechanism should further align incentives for the community to get involved and help increase the value of the SDL ecosystem on its early stages.