How can I get around using Stateflow messages in my Stateflow chart?

I am trying to refactor a big Simulink model, which contains a very large Stateflow chart with many subcharts, and sub-subcharts, et cetera. I want to convert many of the subcharts to atomic subcharts, but there are Stateflow messages being passed all around, which are not currently supported in atomic subcharts (R2019B).

My thinking is that I'll use structure/bus data to convey the same information, but I am unsure how to implement it, especially with the queueing aspect.

This should be enough information, since I believe it is a very general question, but I'd be happy to provide an example for clarification.

[stozaki]

Do you find the following documentation helpful?

Access Bus Signals Through Stateflow Structures

[Thomas Duquemin]

Oh yes, but by implement I didn't mean how do I use a structure, but rather how can I get a structure to behave like a Stateflow message? ie queueing, message deletion after being read, etc.