New ask Hacker News story: Ask HN: Fair to reward founders with equity on performance than equal split?

Ask HN: Fair to reward founders with equity on performance than equal split?
2 by complete_novice | 2 comments on Hacker News.
Forming a company with larger than usual founder base. When originally formed, we agreed with a near equal split with clift and vesting. Now it is being proposed to instead switch to a "reward" system, wherby founders are given more shares based on their value and contribution (which is highly subjective). Proposed that in each year and investment round, overall shares are diluted and more is given to those have placed in more effort, subsequntly reducing the stake of others. This is to be assed via some metrics through milestones or a KPI. This scheme is the first I have heard of it and I cannot find examples where it has been practiced (being successful or not). Has anyone done anything similar? Or perhaps advises for/against? Thanks