Bluetooth on MQ-Pro

Does anyone know of a Linux image for MQ-Pro where Bluetooth is working? I tried the Armbian image from Armbian on the MangoPi MQ Pro! | Bret's Tech, but it is not working. I could build Tina following the instructions in the mangopi-sbc/Tina-Linux GitHub repo, but I would like to know if Bluetooth is known to work on it before I spend the time.

I found https://github.com/lwfinger/rtl8723bs_bt, and thought this might work on the Armbian image, but the problem seems to be that /dev/ttyS1 is not set up for some reason (from the schematics I believe UART1 is used for Bluetooth). I get these messages in dmesg:

[    2.063411] 2500000.serial: ttyS0 at MMIO 0x2500000 (irq = 207, base_baud = 1500000) is a 16550A
[    2.085964] 2500400.serial: ttyS1 at MMIO 0x2500400 (irq = 208, base_baud = 1500000) is a 16550A
[    2.109830] serial serial0: tty port ttyS1 registered
[   16.696827] systemd[1]: Found device /dev/ttyS0.

So ttyS1 exists, but systemd does not create the block device in /dev. Manually creating it with mknod /dev/ttyS1 c 4 65 does not seem to work since trying to read from it gives cat: /dev/ttyS1: No such device or address.

Any ideas on this would be appreciated!