I don’t think the macro usage is 100% necessary; in the case of dynamic text, I’d specify a function in a group’s :description slot (like this; function here) that builds the description from transient state.

Auto-building menus from e.g. makefiles is a feature I’d like Disproject to support in some capacity as well in the future. I came across the transient-compile package a while back while researching ideas; might be of interest to look at.