That option only applies to prefix/suffix commands (as mentioned in VoiceAttackHelp.pdf), so unless you intend on using those, and intend to use "{CMDSEGMENT:}" in them, that option is not required.
Yes, those would be the parts that are grouped into segments, however note that "Please" is a single phrase by itself, and not an optional part of the phrase as a whole.
If the latter is your intent, wrap it in square brackets as well, E.G. "[Please;] can you [enter;input] a key for [processing;evaluating]", which will make that segment 0, and "can you" segment 1.