Doesn't work on Xiaomi Pad 5 Pro (elish) without tweaking

The xiaomi-elish uses a QCA6390 Bluetooth adapter and it does not have an address assigned at boot. I installed bootmac and it fails to work automatically at boot, though it does work if I manually run sudo bootmac after the device boots. I'm thinking the script is not waiting long enough for hci0 to come up before it tries to do its thing so I added a sleep 1 statement at the beginning of the mac_bluetooth() function and now it boots with working Bluetooth. Maybe a sleep isn't the best way to handle this, but I think there needs to be something here to ensure the interface is ready to work on.