The "what's the penalty for being wrong" question is the part I'd keep. That one works at any scale.

But I spent five years on a solo app and never wrote anything close to this. Not on principle event, just the design just kept moving. The decisions that ended up mattering weren't ones I could have named on day one, they were things I cut in year three once I actually understood what the app was for. If I'd written the objective sentence up front I'd have locked in a version that turned out wrong. The clarity came from building the thing, not from describing it first.

For coordinating people or catching a security flaw before it ships, sure, all of this makes sense. Solo just runs on different rules I guess.