This little binary allows you to send any HCI command that you wish to the Bluetooth chip of your macOS device.
user@mac:~$ ./sendhci fc4d0500000000fb
4dfc0500000000fb
HCI Command sent successfully!
040E FF01 4DFC 0006 0000 ea5c f09f e55c ....M......\...\
f09f e55c f09f e55c f09f e55c f09f e55c ...\...\...\...\
f09f e55c f09f e52c 809f e500 2098 e534 ...\...,.... ..4
809f e508 0052 e101 0000 1a1c 809f e508 .....R..........
f0a0 e11c 809f e500 2098 e518 809f e508 ........ .......
0052 e115 0000 0afe ffff eac8 0000 fca8 .R..............
0000 fc00 0000 fcc8 0000 0043 6f70 7900 ...........Copy.
0008 0004 0008 0008 0008 000c 0008 0010 ................
0008 0014 0008 0018 0008 0000 0000 0000 ................
0000 0000 0000 0000 0000 0000 0000 0000 ................
0000 0000 0000 0000 0000 0000 0000 000c ................
d09f e547 0000 eb00 00a0 e100 d09f e500 ...G............
f09f e5a0 d008 005c 0100 002d 2e03 0043 .......\...-...C
6f70 7972 6967 6874 2028 6329 2042 726f opyright (c) Bro
6164 636f 6d20 436f 7270 2e20 3230 3034 adcom Corp. 2004
2042 434d 3230 3435 2028 7229 2042 6c75 BCM2045 (r) Blu
6574