[Nemo]

There is a mistaken impression that 45 days is the traditional build season length, therefore 45 days is the optimal balance of avoiding burnout and producing good results.

We could go shorter OR longer, and people would adapt to make it work. Your team's definition of a sustainable, "sane enough" pace is going to change depending on the length of the build sprint.

We could have any length of build season from 3 days up to a multi-year season. We've seen what RI3D build sprints look like. A team could try to sustain that type of around-the-clock, break-neck pace through 100% of every day of the entire 45 day build season. But they don't.

The longer the time period you look at, the lower the maximum level of average sustained output a human will be able to provide. If people are close to their max over 45 days, that means their level of average sustained output would have to be less over a longer period of time.

Try to imagine the other extreme. If FIRST released the 2020 game after this year's Championship, then this year's 8th graders could start working on their senior year FRC game before they even get to high school. If the system was like that, would everybody automatically start working on it (plus 2019, 2018, 2017 games) for 4+ years running as if it was a long version of the 45 day build sprint? That would cause everyone to get get fired / get divorced / drop out / suffer various health problems / have a mental health breakdown and so on. But really that wouldn't happen. People would adjust their behavior.

1) A longer build season would change some behaviors of FRC teams.
2) If a team tries to sustain a schedule that actually isn't sustainable for them over any length of time, it isn't the rest of the teams' fault for forcing them to do that.