The big puff vapes you mention can have the battery’s swapped (and charged) and are refillable, they are still a waste though because they only last as long as the coil. But it’s a step in the right direction.
I suspect when the ban comes in they’ll just make the coil changeable and keep selling them as there’s no real reason they actually couldn’t be doing that now.
They are refillable at least the lost mary bm6000 is (only one I’m familiar with), it’s actually pretty easy and gives you 10ml in a very small device a big advantage over normal vapes where in the UK the tank can only be 2ml.
They really need to either change that law (2ml is nothing) or start designing reusable vapes that attach the bottle in the same way so you don’t have to constantly refill.
To me the advantage is a small size and the 10ml container being cleverly attached to skirt a silly law.