Absolutely no scaling.
Its the worst idea in video gaming.
Make some enemies too powerful so we know we have to return later. Thats so much better.
The problem is, there's a reason why people do scaling, and it's apparent in BG3.
BG3 is designed so that you can go through the game without exploring EVERYTHING or running into every encounter. But what that means is that if you DO explore everything, it's easy to overlevel. Without any sort of scaling, this means that a player's reward for exploration is a less challenging, less interesting game. It would probably be fine if thorough exploration made later areas a BIT easier, but overleveling enemies by just 1 or 2 levels in this game makes things much, much, much easier.
