However, it lacks one major attribute : initialConfigFunction, that is a code snippet that get executed on every newly created unit frames. This's the theory. Practically, I'm not very used to this because I've written my unit frames using the oUF framework.
To handle your party frames in combat, you have to deal with SecurePartyHeaderTemplate, that will spawn, layout, show and hide the unit frames. You can't do it "manually" ; the whole Blizzard secure and protected things prevent it.