Are you happy with a new build? Equip and lock these runes! That way they won’t be suggested in any further builds.Any change of these options will force a quick revaluation of your builds. And for sure you know what to do if +15 is your only way to go.
You currently don’t want to spend mana for upgrading your runes? Go with the “actual stats” option. Put in some thresholds like Crit = 70%, desired minimum HP values and so on. The optimizer will include these stats into its calculations and suggest the most suitable builds.