> Unless I'm missing something, my tests suggest the D72 doesn't support programming at anything other than 9600. The COM Port->Baud rate option (menu 331) only has options for 2400/4800/9600, and setting anything other than 9600 there still results in CHIRP auto-detecting the baud as 9600.
This is the APRS/TNC baud rate, not the one for the PC, AFAIK, so it's unrelated. Since the D72 uses a USB port for the PC connectivity, it's possible that it will just speak to us in whatever rate we try first, which might mean we're currently auto-detecting something slow. I'll try to get my hands on a D72 soon and see if I can poke around a bit.
The APRS/TNC speed is actually option 311, Int TNC->Data Speed, which is 1200 or 9600 only. AFAIK, option 331 is used for peripheral devices plugged into the USB port such as weather stations or GPS loggers. I only tried it here because it was only radio setting I could find that remotely pertains to the PC serial baud rate.
FWIW, the baud detection in kenwood_live.py:get_id() indeed only tries the baud rate there in ascending order and stops at the first successful one, but even when I manually invert the list, 9600 is the only one detected:
[2019-12-09 15:14:10,563] chirp.ui.mainapp - DEBUG: User selected Kenwood TH-D72 (live mode) on port /dev/cu.SLAB_USBtoUART
[2019-12-09 15:14:10,572] chirp.drivers.kenwood_live - INFO: Trying ID at baud 115200 with delimiter "('\r', ' ')"
[2019-12-09 15:14:10,675] chirp.drivers.kenwood_live - DEBUG: PC->RADIO: ID
[2019-12-09 15:14:11,181] chirp.drivers.kenwood_live - ERROR: Timeout waiting for data
[2019-12-09 15:14:11,181] chirp.drivers.kenwood_live - ERROR: Giving up
[2019-12-09 15:14:11,182] chirp.drivers.kenwood_live - INFO: Trying ID at baud 115200 with delimiter "(';', '')"
[2019-12-09 15:14:11,286] chirp.drivers.kenwood_live - DEBUG: PC->RADIO: ID;
[2019-12-09 15:14:11,792] chirp.drivers.kenwood_live - ERROR: Timeout waiting for data
[2019-12-09 15:14:11,792] chirp.drivers.kenwood_live - ERROR: Giving up
[2019-12-09 15:14:11,792] chirp.drivers.kenwood_live - INFO: Trying ID at baud 57600 with delimiter "('\r', ' ')"
[2019-12-09 15:14:11,896] chirp.drivers.kenwood_live - DEBUG: PC->RADIO: ID
[2019-12-09 15:14:12,402] chirp.drivers.kenwood_live - ERROR: Timeout waiting for data
[2019-12-09 15:14:12,402] chirp.drivers.kenwood_live - ERROR: Giving up
[2019-12-09 15:14:12,402] chirp.drivers.kenwood_live - INFO: Trying ID at baud 57600 with delimiter "(';', '')"
[2019-12-09 15:14:12,506] chirp.drivers.kenwood_live - DEBUG: PC->RADIO: ID;
[2019-12-09 15:14:13,011] chirp.drivers.kenwood_live - ERROR: Timeout waiting for data
[2019-12-09 15:14:13,011] chirp.drivers.kenwood_live - ERROR: Giving up
[2019-12-09 15:14:13,011] chirp.drivers.kenwood_live - INFO: Trying ID at baud 38400 with delimiter "('\r', ' ')"
[2019-12-09 15:14:13,115] chirp.drivers.kenwood_live - DEBUG: PC->RADIO: ID
[2019-12-09 15:14:13,620] chirp.drivers.kenwood_live - ERROR: Timeout waiting for data
[2019-12-09 15:14:13,620] chirp.drivers.kenwood_live - ERROR: Giving up
[2019-12-09 15:14:13,620] chirp.drivers.kenwood_live - INFO: Trying ID at baud 38400 with delimiter "(';', '')"
[2019-12-09 15:14:13,724] chirp.drivers.kenwood_live - DEBUG: PC->RADIO: ID;
[2019-12-09 15:14:14,228] chirp.drivers.kenwood_live - ERROR: Timeout waiting for data
[2019-12-09 15:14:14,229] chirp.drivers.kenwood_live - ERROR: Giving up
[2019-12-09 15:14:14,229] chirp.drivers.kenwood_live - INFO: Trying ID at baud 19200 with delimiter "('\r', ' ')"
[2019-12-09 15:14:14,333] chirp.drivers.kenwood_live - DEBUG: PC->RADIO: ID
[2019-12-09 15:14:14,839] chirp.drivers.kenwood_live - ERROR: Timeout waiting for data
[2019-12-09 15:14:14,839] chirp.drivers.kenwood_live - ERROR: Giving up
[2019-12-09 15:14:14,839] chirp.drivers.kenwood_live - INFO: Trying ID at baud 19200 with delimiter "(';', '')"
[2019-12-09 15:14:14,943] chirp.drivers.kenwood_live - DEBUG: PC->RADIO: ID;
[2019-12-09 15:14:15,449] chirp.drivers.kenwood_live - ERROR: Timeout waiting for data
[2019-12-09 15:14:15,449] chirp.drivers.kenwood_live - ERROR: Giving up
[2019-12-09 15:14:15,449] chirp.drivers.kenwood_live - INFO: Trying ID at baud 9600 with delimiter "('\r', ' ')"
[2019-12-09 15:14:15,559] chirp.drivers.kenwood_live - DEBUG: PC->RADIO: ID
[2019-12-09 15:14:15,678] chirp.drivers.kenwood_live - DEBUG: RADIO->PC: ID TH-D72
[2019-12-09 15:14:15,678] chirp.drivers.kenwood_live - DEBUG: PC->RADIO: AI 0
[2019-12-09 15:14:15,788] chirp.drivers.kenwood_live - DEBUG: RADIO->PC: ?
I can't imagine that the D700 from yesteryear can do 57600 and a modern HT like the D72 is limited to 1980s baud rates :)
That would've been my thought as well :) I'd be happy to try out any other tests you can think of.