Hi guys, A comment from building Spec layouts for widgets (Pharo 6 but maybe applicable to Pharo >= 7): I have built a Spec widget which could have two layouts: #buttonsOnTopSpec and #buttonsOnBottomSpec : SpcLabeledActionsList new openWithSpec: #buttonsOnTopSpec; yourself. SpcLabeledActionsList new openWithSpec: #buttonsOnBottomSpec; yourself. Now if you would have to set such list as a widget in #initializeWidgets, the building process follows its path to #private_buildWithSpec which hardcodes the spec layout to the #defaultSpecSelector (the one containing <spec: #default> pragma). The problem subclassing from DynamicComposableModel / Presenter is that is trying to solve two problems at once: 1) Dynamic adding/removing widgets 2) Dynamic configuration of layout In this case I just need the 2), and I would have to remove inst. vars and accessors in ~20 classes because the dynamic widgets dictionary now stores all widgets, or interject a weirdo between ComposableModel/Presenter and DynamicComposableModel/Presenter. What would you do? Cheers, Hernán