If you tested the mod, then you must have seen that 1914 has some good pre ww2 industrial, communication and electronics techs spread in the industrial and secret tabs. Theres nice land, naval and air doctrines too for pre ww2 tactics. Same thing for the air and naval units techs, theres some techs that could buff up that particular era and it has special techs like the airship aircraft carrier you want to include.
In DH I like how the cavalry techs gives both units and brigades, but it continues to give cavalry brigades up to the end of the line, maybe at some point armored cars can replace cavalry techs and in turn armored techs replace them and this could make things a little more realistic. Real cavalry units techs will die in the late 20s, armored cars appear in ww1 and eventually give IFVs and the armored brigade is just a way to continue the line of light tanks after the medium tanks kill them in the late 30s. This could better represent the awkward position of the cavalry units, they arent motorized or mechanized but they are the ones who create modern mechanized (IFV) and also helicopter units.