You can either make whatever changes to these settings after copying and pasting the [RADIO] and [RadioMenu] sections over the originals in the Mmsstv.ini file, or just copy/paste and change the few settings needing a tweak from within the program itself.
IMPORTANT: Do not modify the file while MMSSTV is running, it will overwrite it when you exit, so exit first, modify, then re-start MMSSTV.
This section is near the middle of the Mmsstv.ini file:
(Note – Change PortName and BaudRate to suit your system!,
also Cmdxx=148 is the CI-V address, 148=94h – the default for IC-7300, check in your rig under MENU>SET>Connectors>CI-V>CI-V Address. If it has been changed from 94h, convert the hexadecimal number to decimal and change Cmdxx to suit)