That is an interesting idea. Structurally, that's not a great place to have a gigantic hole but if it was built strong enough without being over minimum weight it would be pretty neat to operate.

It's not a modification that you could retrofit without adding weight to a boat that's already at (or above) minimum, though.

One other minor drawback...distance racing or other forms of racing/sailing where you need to hoist on a port tack.