Still unsuccessful after several attempts.
Based on https://github.com/openocd-org/openocd/blob/master/tcl/interface/ftdi/ft232h-module-swd.cfg, I tried all combinations of
ftdi layout_signal SWD_EN -data 0
ftdi layout_signal SWDIO_EN -[n]data 0x20
I was unable to get past "Error: connecting DP: cannot read IDR"
Schematics would be very helpful, but based on previous posts I don't expect them to be shared.
Is the TMS output enable active high or low?
If there are buffers to isolate the FTDI chip from the external interface due to different voltage levels, I expect the TMS input to be routed to a different input pin on the FTDI chip. Since I've seen HS2 drivers for cJTAG I expect this connectivity exists. I don't need complete schematics, but the connectivity between the FTDI chip and external interface would be extremely helpful.