Just for fun.
\alicespeaks Are you ready?
\bobspeaks Yes. On three. One…two…\strut% add space when missing descenders
The use of \speaker is definitely the way to go since you need to refer to some entity that shouldn't appear in the Dramatis Personae, yet you're right that you shouldn't have to hardcode the names of the characters into the argument of \speaker in case you change the names to which alice and bob refer.
I see that the dramatist documentation says that \...