I have 2 FDK pbulbs that came out of dormancy late. One has a growth about 1inch tall with many roots going. The second has a tiny growth going with roots but it's very behind the other one in terms of development. Should I keep the smaller one with the bigger or pot it separately to allow watering when they're ready?
Leaving the bulbs together will provide a plant with more vigor. If the larger growth is only an inch long, you have some time to wait anyway. Start watering when the roots are fully 3-4 inches long; the leaves should be opening up by then also. As long as the bulbs are not shriveling excessively, it is doing fine.
I totally concur with Fishmom. In general, don't be in a rush to divide any plant. You need multiple growths (with the leafless but firm back bulbs as well) for the plant to have the energy to thrive. This plant is at least several years from needing dividing.Especially, Catasetinae really need all that stored energy to survive dormancy and regrowth.
I'm unclear from your original post: are the two pseudobulbs currently connected? If so, I concur 100% with the others here. If not, pot them up separately.