Bingo, I think this hits on the real key... higher VMG by bearing away, and focusing on that within a fairly broad definition of "planing."Define to windward, 1 degree above 90 degrees to the wind is to windward, that is certainly achievable. Hard on the wind highly unlikely ..
30 years ago somewhat younger and fitter than now, in 20 - 25mph winds and nearly flat water, I occasionally held a plane up to half way between 90degrees and hard on the wind. There was definitely a sweet spot for those conditions. It was possible to overtake some boats that were hard on the wind. You can't sail through 'em, sail round 'em.
It has been claimed that the Aero planes to windward but I have never experienced anything close to what I would call planing when hard on the wind.I suppose the Aero should probably be able to plane to windward also, with more ease since its lighter and faster?