COSMIC Edit is being developed by our manager through personal motivation; who also developed cosmic-text, so this is the perfect playground for simultaneously advanced cosmic-text, and developing useful real world software with it. The git diff view was not yet part of planned designs, but it took only a portion of a day to implement. It adds a useful test case for the cosmic-text library, and improved cosmic-text as a result.
We’re all paid a full time salary to work on COSMIC and Pop!_OS. Each person on the team is going to spend a full day writing software, regardless of what they’re working on, so concerns about burnout are somewhat silly. Burnout is typically caused by working overtime for extended periods of time. System76 has never required developers to work overtime to meet a deadline, and variety of workload can alleviate mental fatigue, so burnout is not a thing here.