I'm guessing that using some clip-on aero bars would make a big difference. Then you're not using your hands to support any weight so the typing would be a little easier.
And if you're doing hours of Z2 training, you likely want to be getting more time in a position closer to what you'd be doing in the drops.
And if you're doing hours of Z2 training, you likely want to be getting more time in a position closer to what you'd be doing in the drops.