Just saw this ... interesting sims by DonVK. Wondering if this wouldn't make a case for a small driver positioned at the top of the sphere to even out the horizontal response, function like active cardioid ?
Opposing drivers, with a deflector (cone, sphere) between them actually works fairly well and helps the horizontal coverage.
I did a quick trial using [PC83 opposed drivers omni test]
I did a quick trial using [PC83 opposed drivers omni test]