Constant BUDGET_BELOW_PLACEMENT_ROUNDING 

pub const BUDGET_BELOW_PLACEMENT_ROUNDING: &str = "chord budget at or below the rounding of placing an instance's vertices in f64";

The input family a compilation is refused with when its chord budget, in an instance’s frame, is at or below the rounding of placing the instance’s vertices (#295): at the translation’s scale before the source is meshed, at the placed vertices’ scale after. No mesh placed in f64 there is within the budget, so none is reported as meeting it.