90W Gan+ G14= portable gaming laptop.

GaN is not a "charging material," whatever that might mean. Gallium nitride is a semiconductor. It's used, among other things, to manufacture transistors. GaN power transistors can offer high efficiency, which means fewer losses/ less heat in a power supply. Which is one of the factors influencing its size.

What about power factor? I can't see it anywhere. That's a rather strange omission.

Isn't it rather silly to refer to yourself in third person like this reviewer? Not that I'm a journalist (or native English speaker for that matter).

Not long ago, I wrote a detailed post on chargers that, among other things, explained why phones like OP3 are not compatible. After all, they don't claim compatibility with USB PD. So, you shouldn't expect USB PD to work. Theoretically, USB PD PPS (programmable power supply) supports what Dash Charge needs. But the phone doesn't support the protocol and so can't communicate with the charger. It can only default to standard USB charging. A device can support multiple standards. But there is no point in trying what's not supported. On the contrary, you shouldn't rely on it being fool proof. Don't mess with it if you don't know what you're doing.

No, the 20 V/ 4.5 A mode wouldn't work at all with OP3. Unless you intended on blowing it up and setting your house on fire. That mode is clearly intended for laptops.

5V/3A, 9V/3A, 12V/3A, 15V/3A, 20V/4.5A should translate to 15, 27, 36, 45 and 90 W. I don't know where you got your numbers (not to mention that you've got 5 pairs but 7 wattages). In my world, 3*5 is 15 and not 18. And so on. Of course, the power supply is going to take more to cover its losses.

Have you investigated why the 90 W version charged the Note 10+ faster than the other two? They all claim, according to your article, 3 A @ 9 V. Yet only one broke 2 A.

Power supply is one of those things that ought to be beefy. Especially if you intend on keeping it and using it for a long time. It's also not the place to skimp on money. They might be relatively simple devices, but quality components cost money and well designed circuits are usually not the cheapest either as they tend to have many, many components that might seem non-essential (which ensure safety and power quality). Not to mention that they take up space. It's one of those things where consumer style review is useless. You need to take it apart, inspect it and characterize it. That's the only way to distinguish quality worth paying for from crap best suited for a recycle bin. Unfortunately, it's all too easy to buy a power supply that doesn't meet even basic safety standards and shouldn't go anywhere near a power outlet. At least here, if you're buying from abroad for personal use, it's technically your responsibility to ensure that the product meets relevant standards. You might want to check with your insurance company and get their statement in writing.

Compatibility shouldn't be a problem. As long as both ends are from reputable manufacturers. And, of course, support the same charging standard. You expect a reputable manufacturer to certify their product. And that should take care of it.

Hello,
Is it usb-if compliant?
A few days ago I had to return my new Baseus GaN 65W because it did not work with HP laptop due to incompatibility with the usb standard.
Regards,
Piotr