While it is easy to damage the sealing surfaces if you're not careful (The same thing could ultimately be said about any scooter),
Yep. But, it is easier to damage them on a scooter that has to be opened up every time it's charged than a scooter that is sealed once and stays sealed (even while charging).
Even the Seacraft Go! - now a $5K scooter - has charging through the hull. These days, once you exceed the BlackTip price point, there are enough options with through-hull charging that I wouldn't even consider buying a "big boy" scooter that didn't have that.