Re: Assessing the state of a split -- wait or add more comb?
The split needs to have comb or combs of pollen and open nectar, as the split loses all it's work force back to the parent hive, so they need food in-house. It is also a good idea to shake or brush in some extra nurse bees from open larva brood comb, to insure enough nurse bees to be able to make healthy queen cells. The brood comb is good, that will give them nurse bees when it emerges, but to make queen cells, you need to add a comb that has a very goodly amount of eggs. Hope this helps.
20+ years, raise my own queens, feed when needed, I treat but have not perfected varroa management yet.