Aside from the questionable utility of adding unnecessary expense to an elegantly simple device, this is spam.

It looks cool enough to me, but as sand said, the market is very specialized. It's hard to know what'll be useful. I don't want one.

When I read your title, I was hoping for a better gas-can spout that would open itself when enough liquid filled it's counterweight.

I find gas can spouts to be imperfect, in need of a better design. Though every time I buy a gas-can they have a new design, I'm just not satisfied. For instance, now they vent down the middle of the spout. I'm glad that the leaky vent cap isn't there, but it takes way-longer to fill the tractor's gas tank because half of the hydraulic diameter is taken up by the vent.

But I expect liquor bottles have similar problems. I know that when I get liquor (seldom) nowadays they have these pour-spouts and even stop-balls in them (I expect to prevent replacing the good stuff with cheaper). I always pull those things out. I have no qualms in mixing brands of vodka. Its just for me or my guests. Takes less room in the cabinet to have only one bottle of every type, not two halves.

I appreciate that you may be a struggling inventor and posting on whynot yourself may get you a little more exposure. I can stand a little spam. Don't make a habit of it.