Really? Bummer. I didn't think it would be that much more complicated, but I'll take your word for it.

Thanks

A 'commercial' hatch rim needs to attach to a flat surface - that's the real reason for a 'recess'. The lower profile for the hatch cover is a side-effect of the need to drop down to a flat plane for bonding the hatch rim.

You'd need a deck paint job to make a recess look good IMO - and that would probably drop the resale value of your boat.
And as Bill said, it's a fair bit of work. I've put recesses and hatches in a number of older commercial (Mariner) boats as well as in strippers.