What is a good design pattern to save data from a data page into a concrete class on 7.2.2?     It looks like in 7.4 and up Pega offers additional support in the form for flow shapes, flow action options, and a utility to save data page data but I'm on 7.2.2 for now.

I'm able to read my data declaratively by using the property setting "refers to a data page" and it works great.  I also need to update this data.   During my experimental phase of the project I've used  an utility shape that calls obj-save.    This works but I'll have to put this shape in a lot of places throughout my flow to handle all of the use cases.  There are a lot of paths through this area of the flow and I can't just find a common place to call it once.    I'd like to avoid creating more procedural code.     Is there a way to do this declaratively?