The thing I’ve found is that riding with hands on the hoods, forearms basically horizontal is quite comfy for a sustained period, you are at least supporting your upped body weight well on your arms, eventually you will have to shift back to the drops, but it works for a reasonable amount of time, just riding on the drops is still better significantly than sitting up holding the the tops, the most physically comfortable, least tiring / stressful position is unfortunately also the least aerodynamic and does incur noticeable drag I find…
Holding on either side of the stem (as I’ve seen some do) I really don’t find anything like as good comfort wise, you might have a marginally reduced frontal profile but you don’t support your upper body weight as well, and just end up a bit more fatigued…
Beyond that you’re probably looking at clip on tri bars if you want more a more aero, sustainable position, which might be OTT for most commuters…
of course the most “Aero” position is no good if it’s also an increased stress position, there’s a balance to be struck between drag and discomfort… IMO of course, I ain’t no TTer though…