I may have been the one who wrote the comment that you quote as "... a sink shape to focus the steam rather than the new flat ones I find everywhere. "

What climate are you in?

All things considered, it may not be that big a deal. I would like manufacturers to stop making these flat bottomed "canopies" and so would you. But, if you have only these to buy in the stores you go to, what other choice do you have? Make your own shape and order it from a company you haven't seen? Maybe that would work.

I live in zone 5 missouri

if you turn the exhaust on high to extract more air than otherwise, you compensate for not having a sink shape; to make this work, turning the fan on higher than otherwise, you must let more air enter the house than otherwise. ("M.U.A.")

there are some months when this is less than desirable, but it's not as bad as it is for those who live farther south or farther north.