Different custom messages for different stages of review in Workfront Proof

Within automated workflow it would be really beneficial for us to have different custom messages for different stages of review.

For example: Stage 1 goes to these people, they get this message. Stage 2 goes to these people, they get a slightly different message... etc etc

We have a range of different stakeholders that need to see proofs for very different reasons and often information we are sharing with one group is confidential from other groups.