Additionally, if you want to sail upwind with a hooter sail you want its luff to be pulled tight. This loads up the bows and negates any hull weight reduction you could have had by not fitting a jib and bridle setup. Basically if you make the hulls strong enough to take the the hooter upwind then you can just as well have a jib fitted for upwind work. With that you can point higher and sail faster.

In very light winds, all sail area below halveway up the mast is mute anyway. Not enough energy enclosed in the windspeeds below this level to make-up a large portion of the total. With high speeds of a catamaran the angles of attack in this situation are very small as well. Same reason why jibs don't work too well in very light winds.

There have been times were it was actually faster to sail downwind without a spinnaker then with a spinnaker due to the wind being too light.

70 degree angle to the wind compared to a sloop rig 50 degree angle results in the hooter boat needed to sail 1.9 times (say 2 times) faster then the sloop in order to achieve better VMG. Normally, light winds are spotty and it is very attractive to stay close to the middle of the course and not be caught out on the far side of the course.

On downwind legs the asymmetric spinnaker sails deeper.

Under Texel and SCHRS (ISAF) the hooter will be regarded as a jib and an extreme large jib at that. Its rating will be a so low that it can never sail to it.

So I don't see much advantage to the Hooter sail.

But I would love to see a direct on the water testing of the theories.

Wouter