This is why I kinda hate 8BitDo's naming scheme. There's 2 version of the Ultimate 2:
Ultimate 2 Bluetooth-Has the Nintendo button layout and is made primarily for Switch.
Ultimate 2 Wireless-Has the Xbox button layout, and is primarily made for PC.
If you have the Wireless with the Xbox layout, it's Bluetooth doesn't register as a Switch Pro Controller, just as a dinput device. It does support the Gyro and analog triggers.
I totally get the frustration with bluetooth, I used a normal switch pro controller for years on my pc and had constant issues with it. That said, I haven't had any issues with my Ultimate 2 Wireless. I've only had it since November, but I haven't had any issues with it disconnecting.
If you want me to test anything on, let me know and I'll be glad to :)