We use PuTTY to align the TCXO on the XG100M. Any terminal program will work as long as you set up the communication properly.
That is much like what I have in mind but the older radios back to the M-PA.
My terminal app I have the port protocols set per documents 119200, N,8.1.
Newer radios with ARM CPUs have a JTAG port, that would solve all problems but like the Hillary CPU, it has no TAP or JTAG. So, the only hope is doing it like 'Programmer' does it.
Now an old project is logging data on the serial port. It will be New Year before I get that together.
If nothing, that will log all the HEX Programmer sends to the client (radio) and the response Programmer expects in return. If that pans out, that approach can be applied to any radio one has the software for, Motorola, Icom, Kenwood, Baofeng, etc. Then one is not stuck with the limits programming software imposes.
Even tweaking softpots outside the box.
73s