I’m a software engineer who has been at startups for roughly 5 years. I’ve seen the mistakes you talk about made before and I’m sure it won’t be the last time. As a pessimistic person I find these things intuitive, I’m always looking for the hidden costs, the hidden “gotcha” that everyone is missing. Often times these metrics are just too simple to know anything truly meaningful. Numbers still require context, but the precautions you noted will definitely help avoid that head scratching “we got no money” moment.