Yes, you can use the "Ask me every time" command to customize a message every time you run a Playbook.
This is useful in use-cases like Gmail messages or Slack.
You can also use the “Merge texts” action to build dynamic texts that can combine fixed messages, data from past actions, and custom messages.
Check the image for this playbook example.
What about Autobooks?
Unfortunately, this only works for playbooks that are triggered on-click. If you set an Autobook with "ask me every time", you will only be able to set those values once.
We’re considering having Autobooks also pop up to "ask you every time". This is a feature request you can upvote, comment and follow up on this Canny ticket.