Problem with dynamic menu in template diamond 5.0 and collapsing submenu-items

[consados]

I use the template diamond 5.0 with primfaces 13.0.3.
I would like to hide some submenus that still have child elements. In the normal p:menu there is the attribute toggleable to implement this.
The menu from the template does not have this attribute. Respectively all hierarchies are always expanded.
There was a discussion with workaround for the normal p:menu:
primefaces/primefaces#2351
If I include a normal p:menu in my sidebar, the toggleable feature works. But the menutree does not look very nice.
There is a property expanded for the submenus in the Builder-class, but this is not taken into account by the diamond-menu
Is there a solution or a workaround for the problem?
Thank you very much

Menu-controller

MenuModel model = new DefaultMenuModel();
List<AdmModul> moduls = provider_modul.findmoduls();

        moduls.stream().forEach((modul) -> {
            //Build Submenu
            DefaultSubMenu dynamicSubmenu = DefaultSubMenu.builder()
                    .label(modul.getModulname())
                    .build();
            //append menu to submenu
            List<AdmModulSub> lst_sub = provider_modul_sub.findByModulId(modul.getModulid()).stream()
                    .filter(f -> f.getParentId() == null)
                    .collect(Collectors.toList());
            lst_sub.stream()
                    .forEach((submodul) -> {

                        List<AdmModulSub> lstChildren = provider_modul_sub.findByParentId(submodul.getSubid());
                        //Node ist MenuItem
                        if (lstChildren.isEmpty()) {
                            DefaultMenuItem dynamicMenu = DefaultMenuItem.builder()
                                    .value(submodul.getSubname())
                                    .outcome(submodul.getSublink())
                                    .icon(submodul.getIcon())
                                    .build();
                            dynamicSubmenu.getElements().add(dynamicMenu);
                        }
                        //Item has chidlren
                        else {
                            DefaultSubMenu mySubmenu = DefaultSubMenu.builder()
                                    .label(submodul.getSubname())
                                    .icon(submodul.getIcon())
                                    .build();
                            //iterate children
                            lstChildren.stream()
                                    .sorted(Comparator.comparing(AdmModulSub::getSubname))
                                    .forEach((submenuItem) -> {
                                mySubmenu.getElements().add(getMenuItem(submenuItem));
                            });
                            mySubmenu.setExpanded(false);
                            if (!mySubmenu.isExpanded()) {
                                log.debug("toggled");
                            }
                            dynamicSubmenu.getElements().add(mySubmenu);
                        }

            });
            dynamicSubmenu.setExpanded(false);
            model.getElements().add(dynamicSubmenu);

        });

sidebar-menu

<ui:composition
    xmlns="http://www.w3.org/1999/xhtml"
    xmlns:h="http://xmlns.jcp.org/jsf/html"
    xmlns:p="http://primefaces.org/ui"
    xmlns:po="http://primefaces.org/diamond"
    >

        <div class="layout-menu-container">
            <h:form id="menuform">
                <po:menu model="#{cMenu.model}"  >
                </po:menu>
            </h:form>
        </div>


</ui:composition>

[melloware]

I think you can just modify the DiamondMenuRenderer.java to do what you need right? The source code is included.