One of our top requests has been to accept any positive response as a confirmation instead of just "1" or "confirm" in reminder replies.
We recently rolled this feature out. It's still "off" by default, but you can enable it here:
We also added a "reply is a positive response" and a "reply is a negative response" trigger for auto replies like so:
This is very useful for follow-up messages/surveys that ask the client how the appointment went. E.g. if the reply is "positive" then you can send a reply back asking them to leave you a review on your favorite review site.
Side Note: One subtle change we made with this roll out is that auto replies do not cancel the default handling by Apptoto. So confirmations will still take place even if you have an auto reply trigger configured.