ConclusionXCube_ActionForm::load() and update() can be used for various variables because these functions are "virtual"(C++) and "abstract". Generated code by cubson uses these member function and switching GET/POST well. The following dialog shows the procedure in cubson's code for editing. You will understand that cubson contrive to use features of XCube_ActionForm.
As you know, cubson observes recommended rules of XOOPS Cube. In editing, Cubson splits the program into three objects, which are the business logic(action), ActionForm and XoopsSimpleObject. Perhaps, the point that you want to edit in generated code is validation and preparation of display. So you should customize ActionForm at first after cubson generates basic codes. You almost always don't need to write code for customizing ActionForm. You may modify XML configuration file and re-generate ActionForm by cubson.
You have just finished learning basic concept of XCube_ActionForm in this section. In next section, you will experience customizing ActionForm by cubson to actually.