Window sills with or without drip groove?

Then my aluminum window sills would have to have grooves as well. Is that now a defect? The drip edge is there to prevent water from running down the facade; this works perfectly for the neighbors who also don't have grooves.

Question about the drip groove on both sides, a water nose will be present:
Is it sensible or not?
Disadvantage as far as I have understood:
aesthetic

I don't know if it is sensible;
Disadvantage that I'm not sure if I understood: mentally.

You want a groove on the underside of the front edge, around which the water wants to run and then be separated by gravity anyway; so which detail is still questionable: a upstand that runs along both right and left sides of the window sill's overhang above the facade?

a upstand that runs along the overhang of the window sill on the right and left sides of the facade?

So far it has been by phone, but I think so.

Was on the phone so far, but I think so.

So you as the thread starter yourself don't really have a clear idea in mind about what the question is actually about?

But ... everyone just uses different terms ....

Ah now yes - an island. That's how I would do it, plus the groove at the bottom just behind the front edge, which is not visible in the picture.