I bought the Carlinkit 3.0 from Aliexpress. I've been using it in my CX-5 since I picked it up. The car has the latest firmware installed.
It didn't work at first and told me "Apple device authentication failed." After some googling, I realized that you can directly connect to the adapter's Wi-Fi. Mine showed up as VolkswagenXXXX, and the password is always 12345678. Once I connected, I updated its firmware and turned on compatibility mode.
On top of that, through Mazda Connect I needed to go to Smartphone Connectivity and change CarPlay permissions to "Always Enable". If you already connected an iPhone through a wire it'll show up there, and the adapter just shows up as "Phone."
Anyways, once I went through those steps, I got to the connection screen of the adapter. Connect your phone to the adapter via Bluetooth and you're good to go. CarPlay connection is done through 5Ghz Wi-Fi and Bluetooth is only used for the initial handshake.
When I first start the car, it takes around 30 seconds for the adapter to connect to the phone, but it's still faster than me finding the Lightning cable and plugging the phone. And the wireless charger doesn't feel like a useless accessory to me then.
There is no difference in functionality between wired CarPlay and wireless through this adapter. I haven't experienced any lags/freezes on the screen, Siri works just fine and there is no delay in phone calls. There is a 1-second delay when you're listening to music, but I have also experienced this on a Hyundai that had built-in Wireless CarPlay.
If you're considering buying one of these, I can assure you that it is not a half-baked solution that works when it feels like working. I ordered mine from AliExpress because I had to wait for my car to arrive anyways, but you can get one from Amazon for pretty much the same price. (At least in Canada)
PS: I mentioned that the Wi-Fi name was VolkswagenXXXX at first. Once it connected to the infotainment for the first time, it changed its name to MazdaXX.