Unstake penalties - apply only when unstaking on a long-term period. We burn only based on the amount being unstaked. Reward tokens are not subject to burn when withdrawing rewards. Once rewards are staked however they are added to the staked amount and therefore subject to the same benefits and penalties.
Max burn is 80% then linearly the percentage drops each day.
Burn % = 0.8 x (A-B)/A
A = total num of committed days
B = num of days from stake to unstake request
For example, committed period is 1 year (365 days) and user wants to unstake after 30 days:
Burn % = 0.8 x (365-30) / 365 = 73.42
In this case we would burn 73.42% of the users’ staked tokens when unstaking.
Based on the above, if you have staked 10,000 tokens, and are withdrawing half, you would burn: 5,000 * 73.42% = 3,671 tokens and you would be able to withdraw the remainder [after 10 days], 1,329.
And lastly, 5,000 would remain staked.