I'd like to use the Powered Up train remote, #88010 as a simple controller (bang-bang only, obviously).
It's Bluetooth, and it shows up as a device, but the PINs 0000 and 1234 don't appear to work.
Once paired, it presumably operates as an input device (?) so would "just work" with Brickcontroller 2.
The remote control uses Bluetooth Low Energy rather than Bluetooth Classic. None of the GATT characteristics require authentication. This means you do not need to pair the device so there is no need for a PIN.
The remote control is not an HID input device, but rather uses a custom protocol that is documented at https://lego.github.io/lego-ble-wireless-protocol-docs/.
You must allow application to access your location then you don't need to pair train with mobile at all.
