Currently cardinality and cost estimates use the default formatting and expose a large number of significant figures (digits after the decimal point). This implies a level of precision of estimates that we aren't providing.

For CE, we could round to the nearest 0.1. For cost estimates, we may need more precision as we can end up with small costs, rounding to the nearest 1e-5 (which is the current epsilon for the cost type) may be sufficient.