If "{CMDSEGMENT:0}" is used with a command that has no dynamic sections, E.G. "this is a test;this is not a test", it will return "Not Set".
I feel it would be more useful if it functioned as "{CMD}" in this scenario, and returned the spoken phrase.
The above would be more relevant when used in a subcommand, as you may not know whether the calling command would have dynamic sections.
However, "{CMDSEGMENT:}" currently returns "Not Set" when used within a subcommand, rather than sections of the calling command's spoken phrase.