I've typically gone a different route and used an ATMega32U2 (or U4) with Dean Camera's LUFA code to create a CDC to custom hardware bridge. Then the baud rate is irrelevant (or you can use it to set modes). I did this because OpenOCD was taking many, many minutes to program a tiny XC95144 CPLD using an FTDI JTAG cable. Yeah, sorry, trying to do it the "cheap way". When I got it working, the ATMega32U2 "serial" solution could do it in 2.3 seconds. Admittedly this was a few years ago, so things have likely improved.
One funny thing I did find doing this; I have not checked recent macOS releases - I should, was that if "Camera" was in the USB Device Descriptor the device would get claimed as a "serially attached camera" and the "serial" port would not show up - doh.
I've typically gone a different route and used an ATMega32U2 (or U4) with Dean Camera's LUFA code to create a CDC to custom hardware bridge. Then the baud rate is irrelevant (or you can use it to set modes). I did this because OpenOCD was taking many, many minutes to program a tiny XC95144 CPLD using an FTDI JTAG cable. Yeah, sorry, trying to do it the "cheap way". When I got it working, the ATMega32U2 "serial" solution could do it in 2.3 seconds. Admittedly this was a few years ago, so things have likely improved.
One funny thing I did find doing this; I have not checked recent macOS releases - I should, was that if "Camera" was in the USB Device Descriptor the device would get claimed as a "serially attached camera" and the "serial" port would not show up - doh.